I bought both the Otterbox Commuter and the Seidio combo cases to compare (amazon return policy). The Otterbox fit to the phone was about 95%, and the Seidio feels like an extension of the phone. It was a little slick initially, but felt great after a couple days. Button access is great, which is important to me since I read books on my phone and use vol to flip pages. I don't use the faceplate a lot, but it comes in handy when I'm traveling and toss my phone into my carry on FTTT. Also when used in combination with a spider stand (Whatever the name is?) I can use it to create a convenient car bracket for my phone.
Drop protection has been good because of the plastic spine, and the raised ridges let the phone sit face down if needed without scratching the face.
Last superficial change I would like to make (form over function) is to find a decent woodgrain sticker to dress up the spine. There are a couple mahogany look cases for the Phone that look really nice, IMO, and I'd like something like that.