I have used Best Skins Ever (x2) on my old 8320 and 8100 and like them a lot. But as soon as I got a Case (pouch) I thought it was over Kill.
I also use and continue to use Rex Regina, for ~$45 USC, they make very high quality leathers, in many colors. I use my 8320 case with my 8900 and even though it is a little too big I don't see a problem.
Both companies are US companies. I say that because the pouch RIM supplies with your purchase comes from China, and we all know what kind of quality control that country has. I remember I put on my BSE and the dye from the RIM pouch turned my BSE a darker color. I have no idea what that was all about or if I was the cause, but I like the better quality of my Rex Regina.
Perhaps the BSE wasn't completely dry and absorbed the dye from the leather case.
Either way, the RIM case doesn't cover the top of the 8900, so don't use it.