RE: XB-70 EDF
Get the highest C value, but stay away from Nanotechs. You won't blow your 45 A ESC if you stay on 4 cell. If you are getting 4 minutes flights, be verythankful. I modified my ESC to a 60A and put in a 10 blade Change Sun fan, 5 cell batteryand new motor. Awesome performance, but got disoriented with sun at 200 ft altutute and crashed. It will fly again but not right away. Too bad, they don't seem to produce them anymore and they are available nowhere. One thing learnt about this crash, this big delta is no trainer and needs a LOT of altutude to recover from a dive. Do not fly it nose heavy (heavy battery) and avoid aerobatics from which you may not be able to recover.