The 10′ poles will effect it some. Overall you look close to expectations, and could improve for sure. We would try a 24 Fury for learning and we think it should push you better. Also be aware of engine height, because if you are pushing into the 6000 plus RPM range, you are slipping and that means inefficiency on performance. Be sure to watch your rooster tail, and it should be no more than cowling height at most running.
Most 300 Pro XS engines do run a 25 or 24 Fury, with your loads the 24 would be our suggestion. Those 10′ poles do add some leverage and weight up high, plus wind drag.
BCB