I'm using a 28-30-950 and I find it is plenty of power. Check out the video in [link=http://www.rcuniverse.com/magazine/article_display.cfm?article_id=917]this review[/link] and see if the roll rate is better than yours. I was using the stock setup.

Something just occurred to me... My brother had a Seawind EP where the two torque rods were too close together and were binding on the block of foam where the wing bolt ties down. Maybe you need to trim that foam block