I bought this for my wife and she loves it... Initially she was concerned about vibration and controlling it but after one use those concerns quickly went away. She says on the higher settings it extremely smooth and very easy to control... when she's using it I can't even hear it, we can have a normal conversation as if it's not even on... It's run time on the battery has yet to be determined, it's used almost everyday by my daughter or my wife and it's yet to need a recharge... It's had a total run time up to this point of well over 3 plus hours according to my wife it's a great gift idea guys !!! I might even get one for my dremmel bits. YES, it's that good...