Well, I'm a convert. I've been flying my Twist with a Magnum .91 4-stroke for a couple of weeks now. For the first 50 feet in a vertical pull-out drag race, the .91 4-stroke wins, but after 50 feet, I think my old G90 2-stroke would win hands down. Like you guys have said, it's not the top end that matters, but the ability to get out of a bad torque roll in a hurry. And while the G90 is a great motor, I like the Magnum better for 3D. The sounds is also better on the 4-stroke and I've noticed slightly better fuel economy. I can hover for 12 minutes and still have half a tank (not sure of the exact size of my tank). This .91 has SO much torque, one click on my radio makes too much difference in the throttle while in a hover. I have an Eclipse 7 (which doesn't provide expo on channel 3 or a throttle curve for the aero program), so I'm running on the heli program now so I can setup a hover-friendly throttle curve. With a 15 x 4 prop and 15% fuel, my throttle mid-point is 30%, which hovers the plane. Not bad. I'm switching to 30% heli fuel but haven't flown yet.