I have had a matching set of DecalGirl skins on my 8900 and my Dell Mini 9 hackintosh for about 6 months now. I am quite pleased with the quality and durability of both.
When I received my skins I also received a custom url from Decalgirl that allowed me to download a custom wallpaper for the 8900 to match the skin.
The skins are detailed, with the proper icons for all the buttons, including the soft buttons on top of the phone (lock and mute). Based on my experience I can recommend DecalGirl without any hesitations.
I use the "Blue Neon Flames" skin on my Storm 2. I like that it covers the front and the back (even the small sections on top and bottom). Installation is relatively easy and is just a matter of lining up the separate pieces. This can be tricky on the front. All cut-outs are there for LED's, headphones, and speakers. I recommend saving your original packaging for storage should you remove the skin and also because so you don't lose your download code for the free matching wallpaper. One problem: When I install my Otterbox Defender over the skin, the extra bulk affects the sensitivity of my Storm 2 causing some buttons to require several taps or not work at all. Take the skin off if your use a multiple-layer case like the Otterbox Defender.
Yeah, they are great! I really like mine, and I do keep the old packaging so I can remove them and save them for later. My only issue is with the trackpad, it is obviouslly a lower surface area than a ball. The skin raises it enough that it almost catches with my fingers when I move my finger around.
Other than that, they are beautiful for a great price than what is sold locally. Shipping to Canada was cheap too.