The ASUS Maximus III Extreme is a damn nice board. It has quite a bit of headroom in it. I was a little disappointed that we could not push farther, but our DDR3 choice would not post over 1440 MHz; it would crash as Windows was loading. We do want to take another look at the Maximus III Extreme once we have some higher end DDR3 and also the final shipping BIOS.
Still, despite not having a final BIOS the board was more than stable and performed quite well. The extra overclocking tools that ASUS included like the ROG connect and BT Connect are simply great. I found that I liked running the ROG connect quite a bit during my overclocking testing (which is how I know that the memory was the limiting factor). In fact, I did all of the overclocking right from my netbook instead of through the BIOS.
The layout on the board was well thought out, too. The staggering of the PCIe slots for quad GPU support was a good idea. The placement of the NF200 was a little off but there was not much more they could do with it than include it in the cooling loop.
The cool thing about the Maximus III Extreme is that you are getting a board that is not only great for overclocking, but you also get very good stock performance. In many cases these two items do not mix well at all. It was something that ASUS emphasized to us; they wanted to create a top notch board for both types of customers. From the testing results we saw it certainly looks like they succeeded.