Ohh, it's on the 360, that would be why I've never heard of or played Crackdown. Unfortunately that also precludes me from ever playing either game, too.
SRIV, like SR3 before it, has made me want to play it so much that I've killed it for myself. Last night I think I pretty much finished all but the last couple of missions and I feel like I've burned out on it, so I want to give it a rest - like I did with SR3 - but I know that means I'll never go back to it (also like SR3). It's not because I don't want to play it, but because I know if I do ever come across it in my Steam library I'll think 'oh yeah, I was pretty much done with that...' and pass in favour of something new.