I have finally found a case that I'm happy with: the Speck CandyShell Grip
I've tried Tech-21 cases, Minisuit bumper, Minisuit Kinnect, Speck Candy Shell, Seidio Active, Seidio Surface equivalent sold at BestBuy, have a Samsung Protective Cover
coming, and just today received the Candy Shell Grip.
I like to carry my GS4 in its case in this vertical holster
(with rotating clip). All cases I've tried fit nicely (and comfortably loose in the holster). The Seidio active fit the most snug due to the kickstand. But it was easy to remove from the holster. However, it was too easy to accidentally hit the power button when removing from the holster.
Overall, I'd say the CS Grip fits the best in the holster as it is just slightly larger (due to the grip feature) than my next favorite, the Speck Candy Shell. I really thought I'd like the Seidio Active the best, but that did not turn out as I thought it would.
My complaint about the original Candy Shell case is simply that it was hard to pick up when lying face down. It offers superb protection... as I accidentally discovered when I pulled my brand-new GS4-32Gb out of my back pocket and just as it started to clear my pocket, snagged my pants and pulled it out of my hand. It clattered to the tile floor from waist height and suffered no damage at all. Neither did the case.
Other than the slick back, the original CS case grew on me and became my favorite of the ones I've tested. The CS Grip tops them all. It will take some doing for the incoming Samsung protective cover to displace the Grip from the top of my favorites list.
I don't see much mention of the Speck products here. But I am more than pleased with them. The button action is superb... not too sensitive as they are in the Seidio Active case. Not too hard as they are in the OBDefender case (as evidenced on my former GN2).
The Speck CS Grip case (and the original CS case) all line up perfectly with all openings and have a two part construction that provides a soft inner shell with a nice lip around the glass for face down protection. It does not interfere with my screen protector. It also has a nice feel and is easy to pick up from the face down position on a flat surface.
This is a keeper!