Hay: Have just finished one. Would not say they fall togeather or are a easy build, but not hard eithr, sort of middle of the road as kits go. Are they worth the time and effort. Simply put, very much so. Started to set up mine with a Webra 50, but the plug blew out at first run, so put a YS 63 in it. Glad I did, thing hovers at less than 1/2 throttle and a excellent power plant for this bird. Is a good stable flyer in odd positions, just keeps on flying as any very good 3d-r does in my view. When I kill it, will build another.