*Written on 9/14/2022*
As stated in my other entries I am not an expert on the subject of backpacking and survival gear. But I do know a thing or two about it. Lets jump into a crash course.
To preface the theme of modern gear vs military surplus lets get a few things right out of the way. Firstly, everyone has different needs or wants. Secondly, you can cook everything pretty much with old tin cans if you had to. Those would be free probably. Lastly, new/expensive/shiny does not always equate to better.
From the experiences I have it took me a while to think of how I could put it into words how to explain how backpacking, survival and prepping gear usually goes.
I came up with this.

Just as the picture states you can pick two of the three items in the "impossible triangle". In general it goes something like this:
If you are low cost oriented and want function and features, you probably will lack durability and quality.
If you are functionality/features and quality/durability seeking, you are going to pay for it.
And if you are quality/durability seeking and low cost concerned, you will typically lack some functionality and features.
I can get straight to the meat and potatoes of it and say the pros and cons generally as it applies to the modern vs surplus argument.
Modern gear:
Latest materials and features
Healthier
More readily available potentially
Questionable durability (cost dependent)
Lots of options
Surplus gear:
Vintage materials and features
Availability is turbulent and sometimes unpredictable market
Bulletproof durability
Options are design and system dependent
Parts and replacements plentiful (typically)
Cheaper
Historical appreciation
Disposable
This write up could be very long going into detail more into each thing listed above but for the sake of time and being concise were not going to explore them here. You will have homework to do about the quirks of each set. I figure the people finding themselves here will already know a bit about the subject matter as well.
Because most of us have to pick two of the three items in the impossible triangle we are left with asking ourselves a couple of questions. What are the most important features and details about the kit I am putting together?
Sure, you can throw all your money into a very expensive and fits every single tiny requirement and need you have. The fact is most people don't have this approach to the hobby.
If this is the case and you are backpacking over a weekend and have mom and dads credit card, your local REI has a Jetboil waiting for you and you can skip reading anymore.
As of the date writing this the market is very up and down for surplus gear. Just a few months ago this would be a very cut and dry bit. I mean it is called "surplus" gear for a reason. This is not the case right now. Lots of specific surplus mess kit systems are becoming harder to find and going way up in price due to world events. This is a big issue as far as potentially contradicting some of the big pros of surplus gear. Its bound to change and get better or worse.
With that disclaimer... lets take a look at a few examples of the modern kits:

This pictured is a very common Stanley Adventure cook set for two. It comes with two bowls, two sporks, and the larger 1 liter stainless cooking container with a lid. This fairly complete set comes with essentially everything you would need for chow with another person for about $44 online. In stores this could be had on sale for about $25 which is a great deal. Weight is claimed to be 440g. Overall I think this Stanley option is a pretty good choice for people who are getting started because its fairly complete and on the cheaper side. It also is multi fuel usable.
I think it lacks some features that some might really like. I prefer metal drinking cups and maybe more durable utensils but this would work fine right out of the box. There are a lot of modifications that can be made to Stanley gear that would greatly improve the functionality. Like a bail handle for the main cooking pot for example.
Here is another example of modern mess kit gear:

Pictured is the Pathfinder School Campfire Survival Cooking Kit. It comes with the essentials for water procurement, starting a fire, cooking and its all stainless. This kit does come with multi fuel optional use. It has a MOLLE shoulder bag, bottle hanger, fire starting materials, a striker, utensils and its made in the style of the vintage USGI setup. It is clearly an updated copy of surplus kits. However, the sizing is different than the standard GI gear from what I understand and it is also not US made. These products are being made in China. This has also lead to quality control issues and a change of the gauge of steel used according to reviewers of the older Pathfinder kits. The kit cost about $105 and its fairly complete.
I do think for the price someone could easily put together a kit nearly exactly like this for a fraction of the cost they are asking. Especially if they did it with milsurp gear that would work great.
How about one more modern kit:

Last modern kit is a Keith Titanium Canteen Mess Kit. Its a super ultralight modern take on the standard canteen and cup with a lid. Complete with a carrying pouch. its no frills, just a canteen and cup and a bag. The entire thing weighs .44 lbs. Its high grade titanium and its being made in China. And it has a lifetime warranty. This is another multi fuel set up but unlike the Pathfinder you need to have the fire part sorted. Price is $159.
For modern gear the titanium kits are probably the end goal. They are super strong and durable, light and sought after but as you can see lack nearly all of the functionality of some of the much cheaper more complete kits. But its simple, classy, and even dare I say elegant to an extent.
Wallet: "are you looking at titanium gear now..."
Me: "... shhhhhhhh"
But what about military surplus? Lets take a look specifically at two sets.

The first kit is the Yugoslavian or Serbian JNA M69 kit. It comes with everything a soldier would need to eat and drink in the field. Broken down it has a 1L canteen that is very tough thermoplastic, a square thermoplastic lid/cup, a larger plastic serving bowl, and everything packs into a thick 2mm aluminum protective cooking pot with a folding handle. And the complete kits would come with a set of utensils and a canvas bag it all fits into nicely. It can be packed away or worn on a belt.
This kit is different because the canteen comes with it and it all nests. This is a great idea for people trying to add hydration to a very small foot print. Its multi fuel compatible and the thermoplastic makes it lighter than a lot of other out of date kits. Cost was as cheap as $16 for a full kit earlier this year. I managed to find one for $25 last night on ebay from a person who lives in my state. With shipping/tax it was $37 and the condition was listed new which is rare. That or it is incorrectly listed. Stateside no vendors had them.
Prices for these kits are wildly different right now and expect to only find them from either collectors or from out of country. Lithuania, Macedonia, and Estonia popped up more than a couple times in my searching from ebay. Very cool and sort of oddball kit that is touted to be a favorite for bush craft and prepping enthusiasts.

The last kit is a Swedish M40 or M44 mess kit. These would come in stainless or aluminum depending on the year and model. They would have a main pot and lid with a hanging handle. Both can be used for cooking. A spirit bottle for the fuel, and a Trangia alcohol stove for the heating. This set up also uses a stove that the whole kit packs back into that doubles as a wind shield. The spirit bottle holds enough to fuel 2-3 days of hot food and drink for most soldiers.
These set ups have become wildly popular because of the fan base on bush craft and prepper youtube. Some have said that it is by far the most versatile and reliable type of kit with a lot of things modern kits should be looking at to get right. Because of this and the supplies drying up state side we have a similar issue seen with the M69. Kits that are mostly complete but used and in working condition can be shipped from out of the country for about $55-65. However, some of the complete set ups with better grading and maybe the stainless variety are showing up at the time of this writing at a whopping $135-160 plus $26 shipping from Estonia. Weight of a full kit is 2kg so its not light by any means. But being bomb proof is the benefit.
There are many other surplus mess kits but these two stand out because of how different they are and how sought after and loved they were. So for me it is easier just to showcase these two and to say you got a lot more digging to find mess kit/canteen systems better than these. These selections should be a shortcut if you are looking into this sort of gear.
So what is the point?
All of these kits will do the same things generally. Why include canteen kits in with this? That is because most like and appreciate having the extra liter of water available if it can be included into a cook set and loadout. Its just a matter of preference and your budget. I also think all of these mentioned would last pretty much forever with basic care and cleaning.
And lets be real, this entry is just a shred of what each one of these options has to offer. I highly suggest diving into the interesting ones and seeing what they are actually about. All of these kits have different features and designs to make them what they are. Oh and I did mention modifications. Many have mods that make them even more usable and functional in the field or on the trail.
Youtube has hundreds of videos from very informative and entertaining people with much more knowledge on the subject matter.
Aluminum? Stainless steel? Titanium?! It all does the same thing. Go with whatever tickles your fancy and your pocket book.
Hopefully these selections give you an idea of what maybe to look for and explore. From your bug out bag, to your car kit, or for a day hike rig, these mess kits will definitely make your adventures more pleasurable.
All that really matters is using what YOU enjoy when you go out into the woods.