I'm new here so I'll say Hi! LankyLefty makes a good point IMO. I happen to have issues when I try to swing HARD or try to get more out of a swing, normally off intended line and lacking distance. I picked up this crazy game on doctors' orders when I was recuperating from a battle with meningitis, which left me with no use of the calf muscles in my right leg. I mention this mainly because I had to learn to swing a golf club without ANY weight shift towards my back side ( I'd fall on my arse if I shifted back at all). Over swinging and USING my arms/wrists consciously kills my distance.
The feeling of a locked left arm combined with, what feels like to me, a half swing, produces balls struck center of club face with optimum distance. This is true for me from my driver to a PW.