I just used my 32R live for the first time Saturday April 28th. I am going to have to say I saw considerable latency between my Laptop running Windows 7 and using the configuration you mention here. (USB) I was not trying to do any recording or playback, just control of the 32R and the latency was considerable.
You could mainly see it in the responsiveness of the meters and reaction to the faders, plus the Mute All button on the front of the machine. All of these things showed considerable latency, the Mute All in fact was horrible in that it took it a good 2 seconds from the time i pressed the button until the system responded and muted and the button lit up.
I am hoping this issue is just bugs to work out in new system. I was feeling a little buyers remorse long about the 5th song of the set. I was able to get things under control once I realized the latency issue and the night went off smoothly.