nigh-impossible to benchmark properly even w/o all the constant updating
There was a guy who used to benchmark
WoW by flying from one point to another, but I think he stopped doing that about a year ago but i had a good idea how good was a CPU for the game.
Patches don't typically change the game's performance much unless there's a major update. On the PTR, you can get some decent benchmarks since there are fewer players (it's mostly empty). If you're flying a route three times and averaging the results, you can get a decent benchmark for CPUs (not perfect but ok).
I know many people who use their computers like I do: they mostly play one MMO (usually
WoW), occasionally try a new game for a few hours, and use the PC for work the rest of the time.