I've had similar experiences.
All of our team's drivers prefer open-loop control for manual driving. Autonomous mode is another beast altogether, but a human driver is one of the better feedback "devices" around for controlling driving.
The only feedback functions that we bother using are:
1) Dynamically shifting between high and low gear on the AndyMark transmission based on RPM and turn rate. Basically, if you're in low gear going more or less straight, shift up when you reach a certain RPM threshold. Thus, when you're flying across the field, you stay in low to get your acceleration then ramp into high when you need it. This method also works well because if you suddenly start pushing, you automatically downshift because the RPM lowers.
2) Drive straightening. If we detect that the driver is trying to go in a straight line (i.e. p1_x is within a tolerance of neutral), we used gyro feedback as the control variable for balancing the motor speeds until our angular velocity was zero. This may or may not be useful depending on how reliable your drivetrain goes in a straight line, but we found it helpful nonetheless. As an added bonus, we found that even if one of our four drive motors died in a match we still drove mostly straight. Just be careful in implementing this, or you'll find that your drive motors will stop turning in a pushing match because they will be trying to slow down to match the other side. It isn't too hard to fix that, however.