i made a comparison thread a couple months ago with some good, objective info on what i saw as the 6 most used roms. all i did was set the pagepool to the same number (20) for each rom, flash it, hard reset, then run spb benchmark. i figured that running benchmarks was a good, fair way to get objective information that's comparable. i also took down some other info like avail ram and what not.
here is the thread, but like i said the info is about a month and a half outdated now as i think most of the roms have been updated since. but, i guess it could still give people a good idea on the actual concept of how to compare roms...