I don't fly as often nor with as much experience as most here, but I have found my Fox .35's to be very friendly and dependable. Except when hot, they often start on one or two flips and perform well on my profiles - better at least than my FP .35 and LA-.40, which are only "OK", though more powerful. I never had a Fox when I was a kid, but I do remember friends and acquaintences frying theirs while trying to run them in 2-cycle mode on their wallowing (poorly flown) Ringmasters. It was a close call for me, since I really liked my first "big" engine, a $5.98-special McCoy .35, which never gave me any problems after being broken in per the instructions. I chose the Fox because of what people have said about its life-span in comparison and because of its light weight. I have not yet been spoiled by using a good modern stunt engine, although I like my little LA-.25 and will love my LA-.46, when I finally use it.
SK