Hi I was looking into buying this case and it looks great, but I have a two questions. The first is is there any major difference between the SUPER SLIM HYBRID HARD CASE and the SUPER SLIM CRYSTAL HARD CASE for the Blackberry Curve besides the rubberized backing? And I have a Best Skins Ever whole body skin on my phone, would this interfere with the phone not fitting in the cases? Other than that everything seems good. Thanks.

The only difference between the hybrid and the crystal cases is the rubberized back. Other than that, they are pretty much the same.
Your second question: IMO, using BES with the hybrid case is not a good combination. I had that setup on mine, but ended up removing the BES because of the fit (hybrid case doesn't close properly).

I have shieldzone covers on the screen and the back of my curve and the Seidio hybrid case fits fine. I didn't apply the front ones.

I have added BSE under my hybrid case. The fit is more snug, and as a result it is harder to get the latches to release when I try to open the case. The BSE helps prevent scartches from any fine dirt that may get under my case (I had fine scratches on my 8700c from this issue).

Alright. Thanks for the information!