I’ve been playing (and finishing ;)) Black on my Xbox 360, as it is one (if not the only one) of the more recent Xbox games that are backwards-compatible. Technically, it is a very good showcase of what is possible on the Xbox / PS2 (as we are used to from Criterion), although there still are some glitches in the emulator (hanging, black overlay on the screen so can’t see anything (which goes away while you open the guide, incidentally)).
The game plays differently enough to other first person shooters (focus on headshots, nearly every enemy has some form of body armor, blowing stuff up, taking cover, big “Matrix Lobby” shoot-outs), but there is not too much variety; but then the game is rather short (which I didn’t mind). The “story” / video sequences are useless and going back to these indiviual missions (which are set in the same region) after the cohesive single-player campaign of something like GRAW feels jarring.
I found it was quite challenging on Normal, you really have to move fairly slowly, going in guns blazing usually ended with me being dead. No infinitely respawning enemies is a plus, a big minus for reinforcements being teleported in according to the scripted progression, though.
Not worth full-price IMO, but if you find it used / discounted (I bought it for 20 quid from Amazon) and like blowing stuff up, it’s well worth it.