On my Nook Color running CM 7.1, I had problems with small buttons up near corners. I never ran stock long enough to determine if this was specific to CM, however. This varied by app, though. Other buttons in the same corners wouldn't be a problem. The Nook app from the Android Market with the icons in the upper right corner was war particularly bad. FWIW, setting my screen DPI to 240 seems to have fixed that problem.
On the Nook Tablet I've purchased for my wife, I haven't noticed any of these problems. It is silky smooth, and now that I've figured out how to get Market apps on the B&N home screen, I'm very tempted to upgrade myself.