Hi csmertx,
Yes, you can tell the molds are getting a bit old. There are a few blemishes here and there on the undersides- not enough to make me not buy another, but if one is really concerned about cosmetics then something to be aware of. The big thing is that if one were to get the non-trackpoint Ultra Classic Model M from Unicomp, the cutouts where the mouse buttons are appear on the standard version. Its almost as if the molds for the original Model M were lost or damaged and had to be remade from the Endura Pro version (just speculation on my part). You can see it here by clicking on and zooming into the photo of the Ultra Classic:
http://www.pckeyboard.com/page/product/UNI0P4A . Look right underneath the spacebar and you'll see the area I'm talking about. Its not a dealbreaker at all for me, but again something to be aware of. From the photos on the Unicomp site, it doesn't look like the PC-122 has this issue, but then its a different body so different molds.
The one issue I've had with the Endura Pro is that the trackpoint sticks up a little but too high above the level of the key caps and can sometimes interfere with typing. I'm toying with the idea of sanding or grinding down its mounting base a little bit to make it less obtrusive.
I'm also interested in the PC-122, if for no other reason than you can never have enough function keys! I learned word processing on these keyboards back in the '80s and always wondered just what the heck all of those extra keys did! If possible, I'd love to make some of them into media keys for things like volume controls, if that's possible. I emailed Unicomp a few days ago to confirm if the PC-122 is Windows compatible since the IBM originals aren't, and the Unicomp rep confirmed that yes, they are Windows compatible.
Robert
EDIT: thanks for the pointer int he Unicomp keys. What I'd love to see also are more case/cover options, instead of the standard off-white and black. Combining those with colored keys would be amazing. Here's a really bizarre want - a backlit Model M. If a kit cold be made for that, I'd be all over it like my obnoxious cousin at a pancake house.