I had a club training officer tell me that my plane was tail heavy and needed a couple of ounces of lead in the nose. Wrong! it was way too nose heavy. I've had "experts" try to tune my 4-strokes by ear. All ended up way too lean in the air. I guess I was fortunate. I started back when you had little local hobby shops that sold magazines and books. I learned a lot by reading AND "comparing" bits of information. I bought a book on RC aircraft design from a modeling magazine this year. Geesh! If you were way into flaps and weird configurations, the book could be helpful otherwise only a few pages were devoted to standard wing-stab and fuselage-tail-nose ratios. The older magazines had many helpful articles on design and building but they died with the flood of ARFs and RTFs. For me, I've bought my last ARF. I've had to modify way too much too often and these were NOT el-cheapo products. I much rather design and build my own. Okay, maybe one day I'll buy an electric mid-size to play with while building.