RE: Precision Aerobatics Extra 260 problems??
I have struggled with the best CG on my Katana MD as well. After many test at every CG position in the 95-101mm range, I have found that High Alfa works well Between 101 to 103 with 103 being difficult to land and a handfull above 50% power, and pattern style is best at 97 or 98mm. Keep in mind I haven't been doing this very long so Daniel from PA may have better information. If you haven't checked out his videos on the How To section of the PA website you should.
Have fun!