PC Magazine writes:
"The OptiPlex is almost double the price of the Lenovo ThinkCentre a61e, but that's because of the OptiPlex 755's larger tower case, faster Core 2 Duo processor, and extra hard drive. In my opinion the Dell system's extras are worth the money, particularly the additional hard drive. The OptiPlex 755 costs about the same as the HP dc7800, which has a faster processor but only 1GB of RAM and a smaller, single 80GB hard drive. I'd prefer the 2GB found in the Dell and Lenovo for running under Windows Vista. The Dell's expansion space and aforementioned hard drive give it the nod in this horse race.
The Dell OptiPlex 755 is the hybrid SUV of green PCs. It has more utility than the tiny, small-form-factor PCs (think of them as Toyota Prius or Honda Civic hybrids), but it also consumes bit more power when on. It will serve your users well while saving you money on the energy bills that never seem to end."