My response is based on the 3 cases that have had the absolute pleasure of encasing my S2:
Boxwave Dual+ Holster
Matte finished barely there type case with a "kickstanded" holster. Liked it alot for $12, at first. I couldn't deal with how easy it was for the phone to slip out of the holster specifically when worn horizontally on the belt. While hustling to make it into work once, the phone slipped out of the holster and hit the concrete which caused the phone to pop out the case. Double Whammy! New back ordered, chrome bezel and screen spared.
Awesome protection in a big heavy brick. I didn't like how the bottom of the back in the speaker area seemed to stretch out making a little cubby hole for debris. The hard outer shell should have been designed to encompass the bottom of the phone.
Seido Active Combo
My favorite. Similar design & protection of the Aegis without the weight and bulk plus a holster and built in kickstand. I agree that the black one looks like a grenade; the Aegis feels like one. This one is a keeper.