I can't seem to accept invites or read messages through the Social Club overlay for some reason so I'm not ignoring you Gamble
Since going SLI with my 980ti I keep getting micro stutter every few minutes too! Only on GTA though >.<
Its cool man.
For stutter, turn vsync off in game, put turn it onto adaptive in nvidia control panel. Removed it completely for me.
I'm back to work tomorrow but don't mind running all heists anyway.