The Unicomp is probably the best feeling keyboard available now, but ... I'm going to admit I'm disappointed in what I got vs. what it could be if they did a little more development, rather than just continuing to make what was.
I have a lot of old Model M keyboards, and love 'em. I got a new Unicomp. It is "better" than the original ONLY in that it is native USB. The old tooling and molds, I suspect, have aged. Tapping on the case under the space bar produces a definite "poor fit and finish" rattle, my 30 year old Model M sounds solid.
I got the trackball keyboard -- love the keyboard, the trackball was a total waste of money. There are four buttons on the top, four buttons on the back of the keyboard, handy for however you hold it. EXCEPT -- of those four buttons, only two are usable, the other two are literally not connected to anything, produce no scan code, and are not usable in any way. The four on the back are just duplicates of the four on the top -- again, right and left, and two just going along for the ride. I even shot them an e-mail asking how to use the other four buttons -- "you can't" was the answer. :-/ I really don't find a two button mouse useful in the 21st century. Cost is modest, but benefit is near zero.
The Unicomp is a good basic keyboard, not quite as good as the Model M, but better (by far) than anything else that I've seen currently made. As a feature keyboard, totally disappointing. If you have and can use a real Model M, you will be happier. Would love it if they would provide some kind of macro feature in the Unicomp. Price is very reasonable for a good keyboard (which may well last many computers), I'd rather pay $100 for a Unicomp than the $50 "gamer" keyboard I'm typing this on.
Possible observation: cats may not like to walk on the Model M (/ Unicomp) keyboards. Or maybe it's just "my" cat vs. my GF's cat.
As for the IBM clicky-clicky keyboards being the best made? Not in my opinion. Before the PC came out, there were a lot of very good keyboards out there...and the IBM PC keyboard was in the better half, but I remember one reviewer of the original PC saying, "How could the company that invented the IBM Selectric typewriter produce this horrible keyboard?" And that's the truth. It wasn't the worst keyboard ever, but it was far from the best. Try an IBM 3270 terminal if you ever get a chance, or my favorite, the Zenith Z-100 (not the PC compatible Zenith). The only reason it's so good now is our standards are much lower. And I'm dubious about the clicky keyboards being office appropriate.