Hey there - still running FX-60 also, with 2g OCZ with great timing. Swapped 2 8800gt's for a single BFG 260 OC [216 stream - not sure if I regret it, but the 260 gives better gameplay and much smoother. cant tell about physx] - playing COD MW2 max, dragonage max, crysis mostly maxed. [at 1920x1080 res]. 3dmark06 is aound 10500-11000, depending if I overclock it, but rarely do. It was bottlenecked with 2 8800gt's SLI'd which is why I went back to single.
Built a 720be for my folks with a 4850 - havent gamed on it, but it hits a 3dmark 06 of like 17k.
My brother just got one of the HP's with a 630 athlon II in it - will know how it works soon.
Ive debated upgrading for a very long time, but the system is very stable, plays everthing I want at max except crysis, and runs protools without any problems. Kinda in that...if it aint broke, dont fix it stage.