I just got mine and used it for a bit. It is extremely well built and has nice touches. The rings on the charging surface are tacky; when the glass back of the phone is placed on the rings, it sticks solidly to the charger, so solidly in fact that you'd really have to give it a significant bump to dislodge the phone. Still, the phone is not difficult to remove from the orb and no residue is left by the rings. The instructions in the box even show placing the phone on the charger horizontally or in landscape. I would feel comfortable doing that. How this will hold up over time remains to be seen, but for the moment, the phone fits on the orb extremely well.
To be clear, the bumpers from the play store do not get in the way at all; this charger works with the bumpers on the phone.
It also seems like there is a lot of room for error in placing the device on the charger. I have been using an LG wireless charger that I got at a Verizon store, and the margin of error for placing the phone on it is very small. It seems as if there is plenty of give as to the location of where you need to place the phone on the orb for it to charge. The bottom of the orb is also tacky. It doesn't move around once you place it.
all in all, this is the nicest Qi charger that I have seen. Considering that I paid $70+ for it when you include shipping and tax, it is pricey. But the quality of this product is definitely there.