I just bought this, Playstation 3 version, and no real complaints so far. No real lag issues, load times are decent enough, and in fact because your guitar is given a random amp to play around with, usually end way too soon. Also cool that you can play bass with your regular guitar (set bass emulation).
As this has all the bass stuff included, perhaps it is better than the version was when it released?
So far, really happy with the 'game' (I'm not calling it a real game until there are online leaderboards
).
Now that I have the cable, I may try the Steam version as well, and if it ends up being good, who knows even double-dip, we'll see. I'm not so sure less lag is guaranteed though - PC sound input isn't that hot generally either, and if they did a half decent job with Cell programming (no guarantees of course) then that should be just as capable for this job as the fastest i7s.
So far, very happy!
Took about an hour for it to get challenging.