I like my rappy 90. I wouldn't buy another X-cell personally. I didn't care for either of the ones I had. Haven't flown the others but the rappy does anything I throw at it. I threw the OS C spec engine in the garbage and bought a YS for it. Huge difference. I really like the YS. Starting and break in is a bit harder, but once it is going, there is no comparison. The OS burned up in about 8 runs, the top of the piston came off and as usuall, I had to eat the engine. So far, the YS has more power, and runs great.

For the money, I like the rappy, any of them would do though.