Is it a single or dual?
Is this a single or dual quad-core? If you got single, you might want to do what I did by getting the w3580 and replacing the slower w3540 with this.. that way you will have the top of the line processor for lots lots less.. Just to go from 2.66(which is what I have) to the 3.33 on apple's site is 1200.00.. I only spent 608 for the processor.
It wasn't really cost effective either for 400 more to go with the refurb 2.93 as its not much faster than the 2.66, however the 3.33 is faster than both yours and mine and I have it on the way!