Got given this for Xmas to use with my Nexus 4, and charge it it does. It has no problem that the phone sits in a gel case, and charges it up at the same speed as a mains charger.
It makes a bit of a ticking noise when there is no phone on it, but it silent when charging. I assume that the noise is it polling for a compatible device, it's not super loud or anything, I only noticed it because I put the mat about 6" from where my head ends up in bed. A bit of Googling brought up that other Qi chargers also tick when not charging, so I guess it's par for the course with this technology.
The LED is a bit on the bright side, but I've found charging area to be large enough that you can cover it and still have the phone charged.