I've been flying for a few years now and do mild 3D. I would like to build a 50cc 3D. I was wondering if someone can explain the basic differences between a few different models. What are some of the differences between say a Extra 300, a Extra 330, a Yak 54, SU-26, Katana, ect. I know they have different wing loading properties, flight characteristics and things of that nature but what are the real differences? Which are most popular and why? I'm just trying to figure out what I should lean toward for a build... Thanks!!