Well, one test on a forum is hardly comprehensive. How do you know there aren't problems that they haven't enountered? I'm not saying that I know there are problems, I am saying that it is too early for you to know that there aren't. If you look at the last page of that link you posted, you'll see that people have already found a few minor problems and things. I remember when the 680i chipset came out, everyone though it was great, before suddenly a multitude of problems arose, that are only now really fixed.
Don't forget that the X38 chipset is brand new, and there are bound to be many other X38 boards still to come that may be better or worse (especially in terms of bang-for-buck).
Sorry, I'm not sledging your choice, I'm just saying that you should make sure you've considered all the options before you spend the money (particularly for an expensive piece of Hardware)
Another thing- the Mobo has water cooling slots, are you planning on using a water cooling system?
And yes, the thermalright ultra 120 extreme needs a 120mm fan. Its a very tall cooler, so I'm not sure if you'll get it interfering with the 4 sidefans on the Coolermaster (prolly not- that case is massive), but maybe check around for people who have used this combination.
