I just picked up 2x of the Belkin Grip Vues (clear) for my phone as well as my wife's, as this was the ONLY case available in the DFW area as far as I could tell, and had to get them from Best Buy (ugh). Apple store was a zoo and didn't even have anything in stock that related to the iPhone 4, cases or hardware.
The first thing I noticed was using the Belkin Grip Vue made it impossible to use the iFrogz screen protectors (again the only ones in stock for the iPhone 4) at the same time... major disappointment.
I plan on getting Feathers for both of our phones and the crystal screen protectors in a week or two hopefully when they are available. At least with BB I can just return all this crap within 14 days for a refund. I needed protection until then, especially for my wife's phone as she just tosses it in her purse.