After updating and running stuff again, joysticks center within 0.05 from center. Still not a perfect 0.
However, after playing around with various types of if statements, I'm starting to get the impression that the default way is the only way of making it operate smoothly.
If you look at the
http://web.goodrobot.com/blog/wp-con.../tankdrive.png diagram clockwise, by default we get the "motor forward x3, motor off, motor backward x3, motor off" pattern.. That way there is never a situation where the motor has to abruptly switch directions.
If swapping the reverse directions, we get "motor forward x3, motor backward x3, motor off, motor backward, motor off". That way at some point there's an abrupt change in motors from going backwards to forward. That is the issue I've been having and at this point I see no way of avoiding it.
If I'm wrong, please correct me.