I've used both. I actually like Moto's skin better than Sense, and that wasn't always the case. I find that the Rezound delays just a tad when navigating through the UI. The RAZR was super-smooth.
I found the RAZR camera lacking, but haven't taken enough pics with the Rezound to say it's definitively better.
What the RAZR lacks in thickness/weight it more than makes up for in width. I realize they had to flatten everything for the form-factor, but it's sooooo wide and the bezel is soooo big, it detracted from the experience for me.
The Rezound is heavier and thicker, but because it's not as wide, it actually feels less bulky to me (just my opinion); easier to type with one hand.
Beats is fine, but I don't use my phone a lot for music, so it's a bit of fluff for me.
The Rezound screen, again just my opinion, displays colors more accurately and there is a noticeable difference in resolution. But as mentioned before, the RAZR is much easier to see in bright sunlight.
Having used both, it's 6 of one/half-dozen of the other for me.