No real modding other than the OC...I've only had this system up and running since last June, when I bought the mobo and cpu....
Cutting into the case scares me a bit, cuz the stacker is a beast, but I am thinking of putting in a lexan window on side and liquid cooling if I move up to the X2 4800+. That way, I can get a better overclock.
You have a damn fine system yourself...I looked at your dual core and eVGA and drooled involuntarily.
Also, whitey ford...if you are running 3 dimms they are going to be super slow comparatively.
In my early building days I tested different dimm combos and found a 45-50% hit in games by running mismatched memory or trying to run 3 sticks instead of 2...even after turning off dual mode.
I have 4 sticks of 1GB OCZ platinum, but I can't even use all 4 b/c windows won't see it...they are all double sided too, which is a double whammy.
Listen to cobalt on this one. Take out 1 GB and set to dual channel in BIOS...you will see a difference.