These planes are great! I work with Odawg and The Drake & we've been flying the crap out of these things. Removing the lower wing proved to be fun but I took it another step and reattached the lower wings to ends of the upper wings to make one BIG wing. The climbing is B A N A N A S. Even on the lowest throttle setting. I would say at least 1 vertical foot for every 2 horizontal. Gliding is even better. I recommend that everyone interested in the mods should try it since its easy and non-permanent.
Also, speaking of night-flying...we fly ours in a warehouse & it's very easy to loose track of your Ace in the the joist so I rigged up some nav lights with 3v bobbin type batteries (CR435) and a red LED. Just tape it on and you're ready to go. Mine carried 4 lights and batteries without a problem.