I am flying the Ultimate now. The most critical thing is to get the battery as high as you can on the cabane strut - just under the top wing. It flies great with the Himax 4100 w/ Himax 6.1 gearbox and APC 12-6 slo flight prop. It flew pretty poorly until I moved the battery up high like in the updated instructions. Hovers at 1/2 and torque rools really well.