Currently matchmaking!
Will update this post with my findings. I LOVE C4 and C3 with Default sync so am intrigued to see how this plays.
Update: Ok well, it's zippier with off sync! Aim feels a bit more weightless in comparison to default sync, but the curves still work a treat. I need to play three or four games to get to grips with it before making a decision on Off or Default. Off feels twitchier to me, does that sound right?
Update after two matches: It's really hard to put my finger on it, but it feels everrrrr so slightly off compared to Default sync. Almost like I'm having to work harder to land the crosshair on the head of the opponent (I'm primarily a hand cannon user and don't snipe). It's like I overshoot their domes too easily, if that makes sense. It's a bit like what we were talking about earlier, just feels like it treads that AA line a little too closely for my liking. Going to do one more game and if no change I'll switch back to Default sync.