Yeah sort of got use to the weight now and really liking how much more responsive the left + right buttons are, I'll probably keep the g502 for this reason alone. Still think the fk 1 is better for twitchy play and more precise aiming (probably more down to difference in shape and grip type)
Haven't bothered with the calibration thing, I thought it was always regarded as a gimmick?
I'd try the calibration, I noticed a difference on my mat, but the benefits will probably be surface dependent.