Yea Dave, I can recall several poor kits with the "die crunched" parts. And on the other hand, I remember buying an MRC "Trainer Hawk" back in probably the late 70's or early 80's . It was a .15 size ARF, all foam. Flew like a champ, and I even won a Limbo contest with it and beat out the best flier in the club who had always previously won the limbo. There were some decent ARF's back in the old days. I taught myself to fly on a Sears "Cessna Centurion 2 channel foamie. First couple flights weren't pretty, but it got the job done. I couldn't find anyone else to teach me at the time.
I take some of these comments with a grain of salt at times, like the thread on here that said basically that the Funtana .40 was garbage, didn't fly good, etc. I have one and there are at least 5 others in our club, and everyone loves them.
Installing bigger engines on an ARF than what the mfr. reccomends might also be some of the problem. I know one case where the firewall came right out of the airplane in flight. A prop out of balance can contribute to a failure, then "flutter" gets the blame, etc. Point is, there is a whole load of things that can contribute to an in flight failure that may never be realized. There's still some people that when asked if they "balance their props", give you the deer in the headlight look.
But then, this is just my opinion, and I could be wrong!!
Randy