I've owned a QC for a year and now have an FM3 on the way. I'll post some thoughts on how they compare in my opinion when I've had the FM3 for a while. I've used Fractal since 2009 (Standard and Axe-FX II) and wanted to try the QC when it was time to update my gear. It looked impressive in youtube videos, the form factor was appealing and I liked the idea of supporting a Finnish company.
What I will say now is that I've been quite disappointed with Neural's glacial pace of development. I went in expecting a slower pace than Fractal, but there was a lot of talk about how the development would be faster after they got the big 2.0 update out, which made major changes to the unit. Now it's nearly a year after 2.0, and there's been very little added to the QC. Something like 4 amps, 2 delays, and a few drives. I don't really care much about adding amps or drives, but the fx (delays and reverbs especially) are so far below the standard set by Fractal and Line 6 that it's embarassing. There are so many half-baked or simply missing basic features with no word on if they are even being worked on. There's no transparency on things like FX loop levels or latency performance. They are working on plugin support, but I'd rather not have to pay for extra content.