Do you use a mouse? I've never been able to notice it with a trackpad (because trackpads are inherently less precise anyway, and seldom used for gaming). It has been painfully noticeable on both Macbook Pros I've owned (one circa Tiger, the other circa Lion).
I was thinking the same thing. I've tried the Magic Mouse, Logitech Anywhere, and Logitech Marathon all to no avail. I returned them all eventually and now I'm back to the trackpad.
Just from anecdotal evidence from someone who can detect the lag with 3 different mice, it's not there with the trackpad.
Honestly, I'm not convinced that lag is the problem more so than acceleration. I've never been able to disable acceleration since Tiger, so I don't have that information. Since it's quite reasonable to have acceleration with a trackpad, I've never had any problem with Mac trackpads.
Personally, I use a mouse all the time, I'm not a fan of trackpads. I'm not much of a gamer, though, which may explain why I haven't noticed the 1/30th of a second lag.
