Why 4x4?

Expensive, Hot, Loud, Not the winner. Those might be reasons not to build a 4x4 machine. I think though, that there are some solid reasons to build this system, and to start using this platform. So here are a few...

Dual processors.
I think we've all wanted dual processors at some point in our lives and this is it, finally, a dual processor desktop platform that we can all use. Granted, ASUS seems to think that this is a "server" motherboard, but I would tend to disagree. It lacks the Buffered/ECC ram that would make it a stable and reliable addition to a server room. The disk controller is not fit for a server environment either.

Upgrade path.
One thing that I like about AMD is that there is a decent amount of life in their products. Socket 939 is still alive and kicking, AM2 should be around for a while as well. The 4x4 and Socket F is it's own thing as well. If you want to upgrade in 12 months, it will be possible. The same cannot be said of Intel who has an external memory controller that frequently requires a new motherboard with the purchase of a newer processor (though the new 5300's are pin compatible with previous motherboards). More than anything I bought this system for this fall, and the 8 cores that I will be able to plug into my machine. It's going to rock.

IO.
AMD has an excellent architecture for I/O. My tasks vary on a day to day basis, but I felt that AMD would provide the necessary bandwidth for all of my tasks and more. So far this is the case. Though the broken ethernet controller is a disappointment.

Speed
Despite losing out to the QFX, it didn't lose by that much and in terms of cost, the board and chips for the FX70 are about the same price.

Conclusion
Pick what you want - there is more than enough processing to go around. I like AMD, I think they have been innovating and I want to support their products. This purchase hasn't been by the numbers, but I'm very happy.