I am typing on the E6400 machine right now. Short of a small chip off the case from a ... user error ... its been a great machine. I traded in a Thinkpad Z61T for it, but mainly for the processor (the Z61 I had was a core duo, instead of the core 2 duo).

If that wasn't an issue I would still have the Thinkpad. It was a good machine. The Dell is a good machine as well as a 2nd choice.