I own a DR1 and QR1 as well as the Helimax 1SQ so I am familiar with RC aircraft. I would not advise anyone to purchase the QR1 because it is made poorly and I have had nothing but problems with it. Out of the box it flew like a champ but after a few days and minor crashes (bumping into a wall/ falling 4-5' to the ground on carpet) the QR1 would start to intermittently change the throttle. The battery was fine and under testing it would have the same problem using a different battery. I contacted Traxxas and sent the QR1 in for repairs. They determined there was a problem with the main board and sent me a replacement. The replacement was a used QR1 that had a battery left inside it. I instantly tested the replacement only to have the same problem. I called traxxas again and was told they do not ship replacements with batteries included and to send them back the QR1. They sent me a new in box QR1 (looked used) and once again the same problem. I tried to tell them it most likely was the controller but they only wanted the QR1 back again! once again I sent it back and was told this time there was nothing wrong with it and this was the last time they would honor the warranty. I am now the proud owner of a QR1 that does not work.