I'm one of the few who never had issue with the old x5000 speed-up on my pretty strong PC (I had similar issues as others on my crappy laptop though as others have commented), but the new fix seems to bring me down to around x2600-x3100 during fighting activities even on my PC, all other activities seem to be fine going at the full x5000, not that I have extensively tested it with everything.
Viewing post in Cycle of the First Dawn comments
I was in the same boat that the old issues w/ x5000 didn't have much of an issue for me, when I would tab back the speed would need to ramp up from 4000 or 4100 back to 5000 but it would be done as long as the tab was active.
After Hotfix, I get around 3500-3800/5000 when wandering and it visibly looks clunky when doing fighting.