I can confirm that they fade somewhat. My Choc, which has seen about four months of heavy use, is starting to fade on some letters. It's not terrible, really, but if you're really into keycap aesthetics it might bother you. I can't speak to what's available for replacement keycaps for the Choc Mini...but I would suspect that finding caps with the front-printed function key & numpad symbols might not be so easy.
It really is a great board, though, and I think quite well-made. I think it may be against the prevailing wisdom, but I prefer my Choc Mini to my Filco TKL, both for the more compact layout and the slightly "chunkier" sound of the keys. My only real gripe is that I use Home and End far more than i use PgUp and PgDn, so I wish Home/End were the defaults and PgUp/PgDn were accessed through the Fn key. (I just use Autohotkey to reverse them...it is a pretty minor gripe.)