I've been building gaming systems for 6 years and have used a few motherboard companies (Gigabyte and EVGA). Asus is the latest that I've just used because I was so fed up with EVGA and their customer service.
When I bought the x58 EVGA motherboard I was experiencing some issues. The GSKILL ram i used which was on the approved list wasn't showing the correct timings as well as correct RAM speed. No matter what you did to change either issues; you would get Blue Screens of Death aka instability. To keep from this happening, I just had to let the system set it's timings and this resulted in underclocking. Non gamers wouldn't care but gamers might give them headaches. Im anal, so it bothered me every time I turned on my system. Another issue was the malfunctioning USB ports. It didn't matter whether it's the front USB ports from my case or the motherboard ports on the back; I sometimes expierenced freezing if I plugged in ie. charging my phone, plugging in my printer. I registered the board and had some back and fourth tech help with EVGA's tech service. When things seemed to be running fine, I again was experiencing some issues. When I contacted EVGA they claimed that my motherboard was registered under another person. After thinking about it, I explained to them that I only registered it and it's probably under my old earthlink account that I since closed when I switched to FIOS. I even told them my old email address. They emailed me back asking for a receipt. I emailed them my receipt (from a online retailer I can't mention here). Then they requested a picture of my motherboard in my case showing the serial number. I did that. Then I get an email stating that it's registered under someone else. After pressing them; then they had the guts to say that the board was never registered.
I was going to wait for Intel's Ivy Bridge but didn't want EVGA anymore. I was researching until I saw that the Asus Gen3 boards possibly support both Sandy Bridge and Ivy Bridge. Asus as well as the vendors that sell this board do claim that both Sandy Bridge and Ivy Bridge will work on this motherboard. Until Ivy Bridge is available, I will just say that it's a possibility. Several people have recommended Asus and this time, I decided to go with Asus. I'm glad I did!
The easiest manual to ever read. Everything was clear and precise. The pictures were easy to follow. You could not mess up where the case wires attach to the motherboard and that is usually where I shine (yes, I was being a smart *butt* :) The pictures were clear and hookup was a breeze.
Where the CPU is located, if you use a aftermarket heat sink like I did, It's best to research whether or not it will block a RAMM socket. The RAM is close by. Otherwise, it's best to get LP (Low Profile) RAM. They are simply, the RAM without the huge heat sinks. My CPU heat sink is the CM Hyper 212 plus. The ram used were the Corsair 16GB (4x4GB) ddr3-1600 LP (they have what looks like blue jackets on them). The last RAM socket comes very close to the heat sink. If you put the RAM in after the heat sink (before attaching the fan) then there are no clearance issues. The SATA ports are easily accessible for your storage drives. The only possible issue you might have is if you have a SATA DVD or BLu-Ray drive in a full tower case. The distance could be an issue. I didn't though. Just throwing it out in caution. This motherboard does have 2 PCIe 3.0 slots. Surprisingly, the PCIe 3.0 (1st slot) doesn't block the PCIe x1 slot which allows you to fit a sound card (that uses PCIe) easily as the case for me. The 2nd PCIe 3.0 slot is further down. If you crossfire or do SLI, the 2 PCIe 3.0 slots will run at x8, x8.
After firing the system up, the UEFI BIOS screen is great eye candy and so much easier to read than the BIOS we are use to seeing. In my opinion, the BIOS screen doesn't look as scary and imposing as the "regular" BIOS screens we are use to seeing. Asus also included a GPU accelerator to increase performance of your video card. It also has neat tools to over clock safely. I'm not an over clocker so I can't comment on either of these tools.
All and all, this is a great motherboard. This was probably the easiest out of all motherboards I've used.
My system as of 1/6/11:
i5-2400 Sandy Bridge (until Ivy Bridge is released)
Corsair 16GB (4x4GB) ddr3-1600 (running at 1600) LP (Low Profile)
Corsair HX850w PSU modular/continuous power
CM Hyper 212 plus (heat sink and fan)
CM HAF 932 Full Tower
Auzentech Forte PCIe (XFI sound card)
Logitech Z5500 Digital 5.1 speakers
G15 Logitech Gaming Keyboard with LCD
G500 Gaming mouse
LG 24" 1080p (1920x1080) LCD
MSI PE/OC GTX570 (until Kepler is released)
Asus Gen3 Pro P8z68 motherboard
Samsung SSD 128GB (Windows 7 and drivers) SATA 3 (6GB/s)
WD SATA II 3GB/s 350GB Velociraptor w/ Steam and games
WD SATA II 3GB/s 1TB Caviar Black (not hooked up, used as a backup).
Windows Experience Score 7.5 because of the CPU which was rated at 7.5