I've got one. It feels nice, as slim as no case. But it does degrade signal a tiny bit, also a b!tch to take off, and the charger doesn't fit all the way which is my biggest issue with it or I would be using it. Otherwise it's okay.
I'm bringing this thread back from the dead since I ordered a different version of the Crossline bumpers from eBay. Its on it's way from Hong Kong and I'll let you know if its good or bad once I have it hands on. The black one looks nice as it is a Matte finish.