I tried the pro version. I would not use it on a professional level as I already have two arrangers. It does require a lot of style tweaking to my satisfaction and as I said its a lot easier just use what I got. Now on the plus side, for the price it does have a great interface, and does a lot for its concept . It's fun to play around with, but , it's not really for me . Btw Roland has a app that is simular that is used with the bk series arrangers.
Offcourse the styles require a lot of edditing if you dont use a psr or other GM2 compatible Yamaha instrument as your soundsource, after all its the Yamaha style format.
But at that price, for people who use styles once in a while, its a great buy for the money... I dont think its yet a replacement...