Well, I got the Rimfire today. Put it in and took your suggestion on the 10x3.8 prop and used my Great Things 1200 3-cell pack (untill my 900s get here). My RTF weight went up 2oz to 13. The plane has been transformed! [X(] The Rimfire has ridiculous power with that prop. Plus I was getting 15 minutes of HARD flying. I also moved my CG more forward and ended up about 1/4" behind the recommended spot. It seems to lock into the hover a little better there and overall flight seems better. The only thing it seemed to hurt was the hands off rolling circles...just couldn't maintain the altitude. Once, I put it into a hover and put in full right aileron. It "locked" in with the tail wobbling a bit, but just stayed there...I went up...I went down...just rolling away. Finally the wind pushed it out of my flying area and I pulled out of it. I can't get enough of this crazy thing.

In its portly state, it still flew VERY slow when I wanted it to and seemed a little more stable overall while maintaining its incredible agility. It put a good bit more strain on the landing gear, but the plane survived all the bumpy landings unscathed. I fly over grass. I just wish it was not dark here now...