I have owned my Flutter-By for almost 4 years and itís a great flyer. Simply said, If I could only keep one plane out of the 16 planes I currently own it would defiantly be the Flutter-By.
Mine has an E-flight Park 400 920KV Outrunner and NO itís not under-powered!
You see I actually own one so I can comment truthfully about its power and performance rather than speculate that itís under-powered. I have never regretted buying this plane!