A lot of returns reported, yet a lot of folks love their Crafty/Mighty. When I went for a Crafty they were only months on the market, with great reviews and not so much track record. Full retail then was $399 for Crafty. Loved it immediately. Sorry to send it in for warranty, but Pax was waiting on the bench (a back-up is a must). With second Crafty, hated to send in and really didn't like 50 bucks invoice for battery. Second one failed, hated to send it in, but got a new-in-box replacement. #3 crapped out and I upgraded to Mighty for 60 bucks. So, I'm now in for $508 US all together and I've got about 8-9 months' ride left on the 2yr warranty.
All this background is building up to say I think this Mighty thing is awesome, and now that I see some retailers are occasionally selling a Mighty for $340, I would do that and start the ride all over again. My use pattern apparently, ahem, over-works Crafty, so I probably would not get that one. Almost 7 months now on Mighty and function is great.
My experience is limited; so many I've not tried, and so many new ones coming along all the time, but the Mighty does indeed kick butt and, for me, has not been any trouble.