I'll take the Rezound's thickness any day.
Look at the Razr. The claim is that it is the thinnest 4G LTE smartphone at 0.28 inches. But what about the bulge at the top? My OG Droid is thinner than that, if you only measure the lip at the bottom. Lay the Razr on its back on a table. It's only supported in two places, along the bulge on the back and along the bottom edge. Then sit on it. Can it withstand the pressure? There are early reports of the Razr cracking. This may be one of the reasons. Kevlar backing and Gorilla glass aside, I don't think the Razr can withstand that much flexing.
Look at the Nexus. Curved face, at 0.37 inches along the thinnest part, not counting the bulge at the bottom. Lay the Nexus face down on a table. It is curved, so it is only supported along the top edge and bottom edge. Sit on it. Can it withstand the pressure? Who wants to try it? Or put the Nexus on its back. The bulge on the bottom still keeps the phone from lying flat, so it is supported along the bulge and near the top. Can it withstand flexing in that position?
Look at the Rezound. Put it face down on the table and it is supported all the way around. Put it on its back and it is supported by about 75% of the back. Who cares that it is 0.54 inches. I put a silicone case on mine, and it is now about 0.68 inches. If it was over an inch thick, it might feel like a brick, but the difference in the feel of 0.28 inches vs. 0.68 inches in the hand is insignificant. (Does holding a 3 x 5 index card vs. a 3 x 5 notepad make that much difference in your hand?) Structurally, the thickness makes a big difference.
I would hope that those who are contemplating the Rezound vs. the Razr vs. the Nexus would give some serious thought about the structural integrity of the phones.