My first indication that this might run poorly was the 1.01 patch being over 2gb. I think it's safe to say that if you need to alter that much code post-release then you've done a crappy job.
Anyway, I notice far more lag than I should online, and the framerate isn't great either. They couldn't even get the opening scenes right. When you first walk downstairs into your safehouse it almost freezes. And there's a lot of "waiting for the server" before and between matches.
I bought the original on release day, and it didn't have nearly this many problems.