IMO as long as there are Scale Flyers there will always be noisy gas engines. Electric is gaining popularity because the technology is getting better, but as long as full size aircraft make noise, I believe that the majority of the R/C ones will to. With this said though there are alot of flyers who could care less about scale flight, and will drop in their Plane whatever is the most convienent for them, and whatever can supply the best power to make their Plane hover. I love the noisy little 2 and 4 stroke engines, but I also have some electrics and am glad to see the tech getting better all the time.