Steve Westerfeld  (Retired commercial pilot with over 35 years of flight experience)
 
I started flying Quatos early on in its development.  Since my very first flight I was hooked and have pretty much forgotten about PID. I wouldn’t think about building a multi-rotor and not using it.  The control feel is so much superior with a very quick precise response.   I have yet to build a multi-rotor that on its first flight with default settings that didn’t fly better than any PID machine I’ve built.
 

I would fly it for the feel alone but it’s ability to adapt to change makes it a much safer flight control system.  If you put on a bad prop with less pitch than the others it will reference that lower thrust engine and match commands to the other motors to keep in balance and still have full control.

When we first created the M4 microcopter we didn’t think we could use Quatos. Although it flew very well we immediately missed not having the feel of Quatos.  It turned out it could be adapted with out too much of a problem and has made it real delight to fly. I would recommend it as a good way to get introduced to the new control system.