Flew my new Panther yesterday with an os25fx. It is a new motor so I was running it rich. The plane wasn't too fast at first but as I leaned it out it started to go pretty good. The plane flew very easy and fun. Next weekend is combat so I will lean it out some more and see what happens. My Predator with it's os46fx still screams. I interested to see which one I go with, but either one will do the job nicely.