I found moving the CG up to 93mm was a huge, desirable difference. I tried playing with the wing incidence and it didn't improve flight, actually seemed less agile.

In the Super Decathlon forum many people say the CG in the manual is wrong (100mm behind leading edge). Mine was taking off well (use very light rudder input, can always add more, but once you over correct you're done for!) and flying well after removing tail weight.