I've tried both ways and.......
I cannot tell any difference. I appreciate that with vsync off you are not seeing all frames but I have never fully agreed with the "Rubber bullets" syndrome. Agreed you might possibly miss hit sprites on your FE but vsync on or off should make no difference to the damage reported to the host, so if you hit him often enough he should go down. Your monitor is an output device (it reports what has happened it does not tell the host what you have done). Hell turn it off and use the force

So... IMO it should make no difference other than in extreme cases where your system is dropping a lot of frames and you do not see all your hits registered but they still happen. (But then again I can't hit S**T so what do I know).

TTFN
snafu