The age-old question where no one can agree to a consensus - is buying old or buying new the best course of action? Especially in beginner terms. Indeed, it's not a decision to be taken lightly since it may have real effects on your experience when you receive the keyboard and for many years to come.
This page will attempt to outline the benefits and drawbacks of either course of action, hopefully allowing you to decide for yourself. At the end, a small discussion is also given for the same debate in a Model F context. Some people will have different views on what's exactly a benefit or drawback, so don't be surprised if you see contrary points elsewhere. Note: this comparison is specifically for buckling springs keyboards. Quiet Touch rubber dome, M3/M4/M6 buckling sleeve, or M7/M8/M9/M11 point-of-sale Model Ms are not considered.
Despite the fact that Unicomp's existence is now widely known, a vintage IBM-branded Model M is still what most people think of when they think about a Model M. They are typically large keyboards with the signature silver-square, grey-text oval or blue-text oval IBM branding and an immense cool factor to boot. The earliest of these Model Ms have the 'tankiest' build quality and the timeline of the vintage era is littered with many unique and collectable variants.
Despite the fact it's been decades since their manufacture, finding a new-old-stock (NOS) Model M is a possibility. The reasons some go unsold vary, but NOS can eliminate the first drawback listed about buying old/used. The fact you could be the first user of such a keyboard is definitely an attractive prospect. However, buying a NOS keyboard is still not a clear-cut perfect world option.
Obviously, they're likely to be costly. You still won't get a warranty like buying a brand-new Unicomp. And, it's still possible it could have technical issues. Firstly, rivets could still be lost due to poor handling or environmental conditions. Secondly, the keyboard could be dead from the factory, with this fact being unknown since the keyboard was never opened or tested.
In recent years, Unicomp has rapidly become a candidate for the most economical way to experience a Model M. If you simply want a no-nonsense purchase where you get what you want and have a warranty to back you up, it would be wise to consider this option.
Of course, there's the possibility of buying a used Unicomp from within the last decade that should be more or less the same as what they make today, right? Not quite. The new Unicomps, the New Model M and the Mini Model M, have only been available since 2020 and 2021 respectively, meaning most Unicomps on the used market will not be made with the new tooling or their improved dye-sublimation quality.
There were two low points in the Unicomp era you should be aware of. Firstly, there was the real possibility of a Unicomp keyboard yellowing if it was produced after 2005. Unicomp's migration from largely PVC case production to PC/ABS blends means some beige Model Ms from this period have been known to yellow with UV/heat exposure. Also, Unicomp's grey keycaps (as in true grey, not the pebble grey that classic Model Ms used) could degrade, producing a sort of greenish colour. This is commonly seen on Model M122s from during this period, such as Affirmative-branded ones. Neither issue has functionality implications but should be noted if you're aesthetically minded. It is believed these issues no longer occur for keyboards produced after 2013, though.
Secondly, from 2010 to about 2019, Unicomp's keycap legends alignment suffered from misalignment which can be off-putting for some. Starting in 2019, Unicomp has progressively worked towards fixing these issues but there's still the possibility of buying a new keycap set from Unicomp that was produced from this period and retained as old stock. However, this should become less of an issue over time.
It partially does. Unicomp does not produce new Model F keyboards, but Model F Labs led by Ellipse has produced and brought to market reproductions of the early-'80s IBM 4704 Model 200 (F62) and Model 300 (F77) keyboards. Many points of the previous comparison apply here. Buying new means you get a fairer deal for a product that guarantees you'll be the first one to use, you have access to extensive customisation options, and you don't have to worry about cleaning the keyboard or dealing with faults (such as degrading foam). However, the F62 and F77 only represent a small chunk of the entire Model F family and they're not official products.
However, there are two unique points regarding the old versus new comparison when doing it in a Model F context; firstly, these reproductions feature a modern controller inside capable of being flashed with xwhatsit or QMK, which will instantly grant it access to onboard customisation for your layout needs. Secondly, the new F62 and F77 are made to match the specifications of the original keyboards as closely as possible, whereas Unicomp's keyboards are based on the final revision to the Model M design made by IBM/Lexmark that already sported some cost-cutting measures to the design.
There is no generally accepted right answer to the question of old versus new Model M. Your choice should be made based on how much effort you want to give in regards to acquiring a good deal and undertaking a possible restoration, your budget, and how much you value classic IBM badges. If you simply want the Model M typing experience with the least amount of fuss, a brand new Unicomp Model M would be an acceptable choice. If you want the coolest branding possible and have spare time to undertake deep cleaning and bolt-modding, seek out the earliest Model M possible for the highest amount of build quality. And if your budget is limitless, go wild!
Mechanically speaking though, either choice should give you a satisfying typing experience. If you need any additional advice or clarification, feel free to get in contact with me or make a post on r/ModelM!