Raptor:

I have the STREAM50 from Hirobo, and is an increidible airplane, is much better than the other options(personal opinion), i have seen the other airplaes fly, but nothing similar as the STREAM, i fly my STREAM with a Rossi .45 Rear Exhaust and a Hatori pipe, true unlimited vertical, the instruction manual shows the instalation of a YS .63 so you are not going to have any problems with the YS.

BUY THE STREAM FROM HIROBO!!!!!