OP I don't own one, and didn't get to fire it, but a fellow from MA did allow me to handle his at the range one day. The safety lever in my opinion is very well done, very "1911-esque"...very easy to flick the safety down without shifting one's grip or anything. I know some people don't like manual safeties at all on a handgun, but personally I can't see that this one would slow one down at all during a draw; split/shot times should remain the same I'd think for the same operator.
I wish that I could give you actual firing experience with the gun, but I kind of doubt the experience would've been much different than another 320 without the lever safety.