those Quads will be a HUGE move up. I'm coming from a Core 2 Quad Q6600 @ 2.4GHz to a Core i7 920 @ 2.66GHz and am seeing a very big performance increase, especially with HyperThreading in some apps.
add in the 3GB in Triple Channel RAM.
and what ever other enhancements they've done.
but I can imagine the jump from Socket 939 Single core to a current Quad, it'll be like being out of the PC scene for 10 years and remembering how fast things WERE, and then seeing things Now LOL.