I did quite a bit of research before I went ahead and bought this case. Seemed to me there are 2 main offerings in this area to protect your phone: Cases that are extremely cheap (around the £5 or under mark) that will be made of low quality materials and most probably fall apart quite quickly, or something around £20-30 that will last. The genuine Samsung cases are ludicrously over-priced and whilst protecting the screen, offer zero protection for the back or if the phone were to be dropped. The S View style cases seemed gimmicky, and from past experience I wanted to avoid screen protectors because my last smartphone has zero scratches after years of use and of course they also reduce the clarity of the screen, and the S4's screen is without a doubt the best out there right now, it would be criminal to stick plastic over it!
So I wanted something that had a flip cover to protect the screen, and some sort of protection for the back without adding loads of bulk and voilà! I found this baby. The phone is encased in a polycarbonate shell which is nearly indestructible (google it) and all the sides are protected (big plus), the camera is also recessed so it wont get scratched. The flip has microfibre to cover the screen, and leather on the outside so it really feels premium. To top it all off, they have strips of D30 (youtube it) inside, which is made up of intelligent molecules that absorb shocks and impact. (awesome, it's basically orange FLUBBER, cooool!)
With the S4 being incredibly light in weight, it is also nice to put this on and make the phone feel a bit more substantial, but even with this I can barely feel it in my pocket, it really is that light!
Probably the best case out there. There are plenty that have a shell on the back (silicone/plastic etc.) but then you have to get a protector for the screen. The genuine cases are just a flip with a replacement back to the phone and offer zero protection. There are leather offerings etc. but as far as I can see nothing comes close to this, it's just got it all going on. Highly recommended.