I have one. It is a thinish leather so it doesn't add a lot of bulk. It fits tight around the phone and it will not slide out accidently at all. I suspect it would not give you much "shock" protection, but it gives plenty of surface scratch protection. There is a strap on the front that you can slide your headphones under. They are all custom right now so you pick your leather color, silk lining type (they have tons of cool linings) and wait. They are hand made so it can take a couple of weeks.
Overall it is a nice sleeve style case. At first I thought I'd like thicker leather, but now i am enjoying the fact that the case doesn't bulk it up. The leather is glossy-ish feeling. I had fun putting some creases into mine to make it look more worn in. This is a sleeve style case and it covers up most of the phone except for the top and the sides down just under the "silent" switch. You will have to remove it from the case to do anything other than listen.
They are a small nice company, very friendly and helpful.
Happy to answer any questions.
I forgot to add that so far sliding it in and out of the case (and it is a very snug fit) has not resulted in any markings, scratches, scuffs, etc on any part of my iphone including the chrome bezel. Very nice.