YEs it is a lot of fun to fly, it looks like some sort of "secret weapon" as it zooms overhead. I have no idea actually how fast it goes, someday I will have this checked by a fellow modeler who has a precision radar gun + he can also record the sound as the model passed by and then plug this into a software program that calculates speed by doppler shift.
The WREN turbine in this plane operates flawlessly and I would certainly recommend it to anyon ein th emarket for smaller turbines.