I HAVE AN EXTRA FROM WM IT IS ASSEMBLED WITH THE STOCK HARDWARE AND AN OS 160 WITH A BISSON MUFFLER. IT FLYS GREAT, I HAVE ABOUT 60 FLIGHTS ON IT AND HAVE NO PROBLEM WITH VERTICAL OR ANYTHING ELSE I WANT TO DO.
AS FOR ALTITUDE I LIVE IN UTAH AT 600 FEET. I DID HAVE TO GO TO A 16-10 PROP FOR THE VERTCAL.