I liked slashdot more when it was plain, quick-loading HTML. I liked most sites more when they were plain, quick-loading HTML. Ain't It Cool News is the only other one coming to mind at the moment, though.
Hacker News is great in that respect -- it's all simple and very responsive.
It isn't the processor time that is taking longer its the transfer time.
I believe current thinking (on non-enterprise sites anyway) is to let the IE people have their square corners, and those on new browsers get all the curvy goodness.