There isn't any bouncing but you can tip it over I guess...though its not prone to doing so. The ducted fans sound like a great Idea but the cowel/mounting is weak and breaks. Its also very heavy and the BCP is already tail heavy. Give it a try if you like, but I have heard very little good reports.

With the CNC airframe....you will have to get creative with mounting the servo's and such. Its not a direct replacement. I also have heard of people getting some serious glitching but I suspect that is due to how/where everything is mounted.

There are some good threads around about that CNC frame....a search might net some more info.