I would expect it to slip after a King Uk service to be honest, they would have used the special ring drive lube as specified by CK, this is perfectly fine for XC etc but for trials it is too thick, i tend to used very light oil in my hub. My hub gave my trouble when i first got it, but after a new set of drive rings it was spot on, lasted 3.5 years before another new set of rings was needed, love my hub, but i haven't realy ridden any other setups properly to compare. People say about Pro 2's being reliable, its ok if you don't mind re-building your wheel every time you crack a hub sheel, which seems to happen with the old and new style ones...... Adam