TBH my experiance has not been great with the GA-Z68X-UD5-B3
This motherboard is regularly known to suffer from a boot loop problem were the machine will not post at all and consistently cycles through the initial boot. It seems to be triggered with a combination of S3 (suspend to ram) power mode and pressing of the reset switch. gigabyte are aware of this problem and have ensured us that it is just bios fault that will be fixed in the next bios update....3 updates later it is still not fixed
Another problem that has recently developed (last week) for me is a very very loud hiss that is coming from the sound. This his can only be described as if someone had a guitar amp with the gain and volume on full and it is very annoying. after testing my PSU and grounds I have whittled it down to the on board sound controller is faulty on my board and I will need to RMA it once I finish this term at uni in three weeks time. I have purchased a £4 2 channel pci sound card for the time being and that has cured all traces of the hiss so I am certain that it is the board.
The good thing is gigabyte have a three year manufacture warranty on all their products and what I have heard is that their returns process is relatively painless and quick.
Don't let my experience put you off though as there are plenty of other members with the same board as me and have not had a sniff of a problem.
For the price, this is one of the better boards in z68 market as it includes ivy support, pcie 3 (with ivy), 24 phase power and many other features that make this board a perfect bridge between sandy and ivy
Also one final note... intel smart response is a must for people with small sized ssd's as it makes operating windows soooo much easier/faster