they do FINE with the 1.20 but mine has LIMITED vertical which is not a bad thing in my eyes. it flies more true to scale for a bipe so to speak. unless HIGHLY modified i can't think of but maybe one bipe that has UNLIMITED performance. i think that if you're looking for unlimited vertical, 3d, and outrageous aerobatics you should look at the ultimate series with an overpowered engine that gives at least 2 to 1 power over weight ratio.

just my $0.02 worth.