very valuable, does not interfere with the reception

From my S3 I knew that quirks are not easy to remove at the edges, so you have to completely disassemble dasn device to the side panel replaced. So I searched the S4 directly after a bumper which looks classy and protects the sides. Apparently disturb many aluminum cases receiving, I can not confirm this - I still WLAN on the top floor, although the router is in the basement (ie without Bumper reception is poor, but because it still comes with envelope they can not disturb ).
The S4 is to grab something bulkier, but also better through the Bumper. Moreover, one can not so easily mistake the side buttons. Overall, a little Iphone look created by the aluminum side panel.
The fit is excellent, the installation no problem. 2 screws are needed, 6 are provided, as the screwdriver.

Let's talk about the disadvantages:
- The Bumper, the device does not fit into planned for the S4 chargers / Car Mounts (ie you need a universal mount)
- No screwdriver can not remove the device from the Bumper (which takes you not to the battery, SD card and SIM)

With the disadvantages I can live, that was clear when buying - overall I am very satisfied.
Saxonia should possibly think about a glossy variant ... that would better fit the aluminum elements of the S4.