Minis took off like wildfire at my track too!
A guy at my track put shoe goo in his gear diff and it had a little more traction coming out of the corner but it did push a lot too.
Also his motor was 170 degrees when he came off after a race. I would go with a manta ray diff myself. I ran with the gear diff for several weeks and it worked well but they seem to pull harder with one wheel than the other.That will make it push one way and corner well the other way. Its just kind of inconsistant.
my 2