The 46 will hover the plane well. Try a few different props to find what you like best. The prop will make a big difference in the way it flys.
Try 11-4, 11-5, 11.5-4, 12.25-3.75, APC's.
Flew one today with a regular OS 46 FS. Not the performance of the 50, but that heli version should be a bit better than the regular 46.
There are a few threads in the 3D section about the Flip. Here is the best.
http://www.rcuniverse.com/showthread...08&forumid=230]