Honestly I think it comes down to what is priority to you. For me I have raved about vzw giving me a vanilla device that is not locked down and pure google so I can get my updates with out worrying about oems holding me hostage.
Others dont care so much about the vanilla android thing because even locked devices have roms. So give and take here. Motorola makes the best hardware hands down and you know you getting a device that is built strong and will last the entire 2 years. The Razr will eventually get ics and blur is more aesthetically pleasing to the eye compared to vanilla android. If you want a solid device and you just root for apps and minor tweaks then the razr may be more for you.
If you big on rooting and hacking you are going to want an open device. I prefer deciding every little detail of what I want on my device, not having bloatware, and getting updates for the life of the device. Also I plan on getting an otterbox so ill be ok knowing its plastic.
Whether you buy the razr or the nexus you are getting good devices. And again this speaks to the growth of android. 2 years ago the choices was the droid and the droid eris. We now have so many great devices to choose from and we know there are more coming along horizon. The important thing is finding the device that fits you because we know that every other month we will see a new device or rumors of new devices and the specs will continue to get better. The best thing to do is ask what you want out of your device, do research to ensure that device will do what you need it to do for at least a year and a half. For every device some one will hype it and others will bash it, listen to both sides and try the device yourself so you can form your own opinions. In the end no matter what device you get there will be another with better specs. So to me I need a device that will allow me to customize and keep up to date with software updates so I am not feeling like I must buy a new device next year because the oems forgot I own the device and are more concerned with putting out a new shiny toy with the next android version so to get people to buy that.