Well I have the Razr, which I absolutely love, my wife has the Nexus...she equally loves. Honestly, they are both nice phones. I have had a chance to play with both side by side now so I thought I would share.
Build quality..hands down goes to the razr..its not only beautiful to look at, but just feels solid. The nexus is nice looking phone, but feels fragile in your hands. Both are extremely light in weight.
Camera..a little closer, but motorola still has a way to go..have to give it to the nexus, although both don't hold a candle to HTC. What only 5MP??? That's right, it's better than my 8 on the razr.
Front facing they are equal.
speakers and call quality you won't find a better phone than the razr..in fact my wife has to use her old smartphone as her alarm clock because the speaker on the nexus is just to soft to hear.
Obviously the nexus has ics vs gingerbread on the razr..I have no opinion on this. I have played with hers, but there is a bit of a learning curve..so I can't say I like or hate it more..eventually both will be running ics, however being a true google phone, I expect hers to get the updates sooner.
Screens: both look sharp..I don't get into the specs too much, If you can tell a difference you have better eyes than me.
The big reason to get the nexus over the razr is the the unlocked boot loader and lack of manufacturer "skin"..however I must say, motorola toned down there "blur" quite a bit on the razr..i don't bother rooting my phone these days, so the locked boot loader doesn't matter to me.
we both are getting decent battery life...what you would expect from a smartphone.
Both have decent storage out of the box...obviously everyone knows the advantages or dealmakers on both for storage and battery.
In my opinion, you can't go wrong with either. I'm not a fanboy of any particular brand, both excel in some areas and lack in some others. the over all experience is great on both.