I got my Otterbox Wednesday evening and have had it on my phone for about a day and a half now...
Honestly, this is the best cell phone case I've ever seen, or owned for that matter. The fit and finish are perfect, very snug and very secure. The rounded corners and the high quality materials used in construction give the phone a great 'finished' feel, very solid. The power/sleep, volume and camera buttons all line up perfectly, and as another poster mentioned make them much easier to use, especially the power/sleep. The covered ports are lined up dead on as well and do a great job of keeping dust and dirt out. The slider works perfectly and is not hindered at all by the case... It slides open smooth and clicks back into place perfectly. Both the top and bottom pieces fit snug and secure; no issues at all with either feeling loose or coming off. Both feel like an integrated part of the phone.
So, essentially, I love this case... highly recommended!