There's nothing different about these battery covers from a design perspective. The one I received fits identical to the stock cover that came with my Tour. In reality what your getting is a stock battery cover with a laser engraved graphic added on the back. You might accidentally end up with a cover that fits more snugly, but it's not intended to improve the fit.
Here's a quote from the F.A.Q. section of Coveroo's website:
"We start with a cover identical to the one currently on your phone. Then Coveroo uses a high quality precision laser to carve the artwork into each cover."
Feels like a getting a coveroo sacrifices protection...unless you get a clear case.
I'd agree with that. I just kind of live with the fact that if I drop it...it's gonna get scratched. I really don't like the bulk that cases add to the phone. I've never tried a BSE, so I can't comment on them. Over the years I've found that I'm really pretty easy on my phones...famous last words...