Ground effect gets a lot of R/C pilots who approach too fast. They think they have a good angle on their approach, then they get into the ground effect and the plane won't settle, so they try to fly it onto the ground. Bad piloting in my book. When I was teaching guys to fly R/C, I taught good approaches with a proper flare at the end to set down.
Quoted for extreme truth.
I was largely self taught on R/C electrics, and when I finally got around to taking some proper lessons from one of the best R/C guys around town, the bad habits I had acquired were nearly all related to set up and subsequent landing as Factor stated. Once you have been taught the proper way to do it, the rest of the flying, at least for me, became easier as anticipating that landing wasn't going through my head the whole time I was in the air doing beginners maneuvers.
Do a google search for fly eagle jets. I was in Taiwan a few years back, and it's like their national pastime I swear. They close down sections of highways on the weekend to let guys fly these 1/5 and larger scale jet fighters off of them. I've seen an F15 doing probably 180 MPH one day, it was pretty amazing.
