Its not that fast throttle servo's are bad or anything...but there are just NOT needed.....imo .15 is the limit for slowness...and my 5955's feel just dandy at that speed.....Ive owned Ace's and other Fast servo's....but none of them held up to the hitec....the 59's kept on coming back for more...where the JR's and Ace's were failing top cases and blowing out gears.....when i fail 3-4 ace's in a row and without a single change to the vehicle and drop in a hitec and the problem Dissapears...that says somethign to you right there.