David, being the "friend of mine" that Flyer95 refers to I can only reinforce his views on MVVS .49 (and.45) since I have one of each and they are very nice engines.
Was surprised that you would have to pay more for the MVVS than the Webra, here in Sweden the Webra is about 50% more expensive than the MVVS.
Attached pic shows my static rpm with the .45 and a 10x6 APC on 0%nitro fuel with 18% oil. To my pleasant surprise that is with an engine that first ran for a whole season as side exhaust before I bought it and "rotated it" into an RE and fitted with mini-pipe. I did NOT expect performance to be so strong after that conversion....
My .49 is even stronger but not by very much.
Whichever engine you buy...Good luck and Cheers..../Harald