Here's some reading to start with: http://www.bit-tech.net/hardware/motherboards/2012/05/09/gigabyte-ga-z77x-ud5h-review/8
(comparison is the Gene, but that is still a Z77 board from Asus). I'm sure you've read the Pro's review on SPCR already.
I haven't heard any bad things about either board yet. Personally have had less setbacks with Gigabyte boards than Asus, but that's just my individual case, and I've liked my last two Asus boards very much. The Asus has verified fan controlling functionality, but the Gigabyte EasyTune might do a decent job as well. EasyTune fan control is not explained in the board's manual, so you'll have to look that up somewhere.
Both boards claim lots of things and have multi-phase power designs, only time will tell which fares better. My pick of the litter was the mATX P8Z77-M Pro.