[Golfer4646]

Team 4646 (my team) used an 8 wheel drop center drivetrain. All wheels were 8 inch pneumatic tires inflated to a firm feel, (if I remember correctly, that was between 30 and 35 psi).
We were running with a 1/2 drop on the center wheels.

It performed well with no major issues, and was only felt unstable when we quickly changed directions. If we had a chance to redo the drivetrain, we would probably do a copy of our original, because it worked well enough. (If anything, the drop would have been reduced slightly, probably to no less than 3/8.)