Yes, Turning it off has gr8 performance but when yur doing ALOT it can slow down.
Thats why manually setting max and min is best for a useable pc. since it wont go to the pf if it isnt needed.
You can c pf usage in task manager it will hand around 1-2% on no load. and even during games its around that. but this gives u flixbility when running ALOT of aplications.