JW , i haven't flown the A-4 on edf yet. I have flown as ducted fan and turbine and loved the way it handles. All with sport wing. Aeronaut fan was $350, Neumotor 1912-1y $200. Castle 110 $225. Go to Dynamo electric for your batteries talk to Randy, nobody can touch him. I'm shooting for 9-10 lb flying weight and will be close to 1/1 pwr to weight ratio i hope.