Not really. I actually came from having tried a Windows Phone (Samsung Focus S) for nearly a month which was incredibly light and thin, so the GS2 actually feels quite bulky to me- the 4.5" screen is honestly a little too big for my liking, but given that the Galaxy Nexus is bigger still I don't see any very viable alternatives.

Another thing to note is that the AT&T SG2 (the one I have, the 'Skyrocket' LTE version) is very new, and really don't have any fully functional custom ROMs yet. I'm using a half-baked CyanogenMod version and there are still plenty of issues.