To me this is a bit of a premature argument as the Rezound isn't even updated to the latest OS.
That's the million-dollar question - what, if any, compatibility issues with Rezound hardware will make ICS a less smooth experience vs. the Nexus? Wait and see, but it's also a total shot in the dark as to which phone will perform better on the next Android version.
Personally, I'm pretty happy with ICS and it's a fairly polished/finished product. Down the road, something like controlling a home security system, media, etc. - some of which is already out there - might matter, and that's where NFC could be worth something. Although I'd more than likely be looking at 2nd-gen there for peace of mind (no disrespect to the Nexus and its NFC).