It was a lot of fun, but because you were in the center of a SPHERE the axis of control was not as intuitive as one might like. In particular, going "up" changed the orbital "plane" (no pun intended) and as a result was going to intersect with the ground unless corrected. You could do a little bit of hackery by squatting down and standing up to change the spheres center but trying turning rapidly in a circle while in a squat, it doesn't work well!
One of the adjustments that was "picky" was setting the vertical stabilizer for consistent yaw. You wanted the plane to pull toward the outside of the circle, it would do that from centripetal force once it got up to speed but before then a bit of help, well helped. Too much though and if you tried to fly inverted it started flying toward you and that wasn't helpful at all.
The best thing about the engines were that 12 yr old me could completely disassemble them and rebuild them in about an hour. That was something you had to do, Cox would "refurb" an engine (which I had them do once when I found a wrecked plane that clearly had been out in the desert for > a month) but once I got good enough at it I could do the refurb and save the $15 + postage that Cox wanted.
Fun times.