I have a loaded down
Dell XPS M1710 and I love it. I actually bought mine from Ebay and saved $1,600 from the price of buying through Dell's site when you figured in tax.
I think that if you find someone on Ebay that has a high feedback of 1,000 or more with 99%+ feedback, seeing that they sold a pile of laptops already, I don't think you'd have anything to worry about.