The use case between K210 and Jetson systems is quite different. I've used the Maix Dock as a smart controller for a custom CNC system, and it performs beautifully. The Jetson line is more suited to systems that are video heavy (low latency, multiple feeds, mixing, processing, etc). The Maix boards just don't have the RAM to deal with that; I've only been able to handle two incoming video streams at low resolution.

That being said, programming the Maix is a piece of cake. The Jetson Nano was very challenging to deal with; the software is unstable in many cases, and the levels of abstraction are all mixed up, and discovering which Nvidia tools to use is an absolute pain (Gstreamer vs DeepStream vs ARGUS vs whatever else Nvidia pumps out this year). Also, I had way better support from the Maix community than from Nvidia. Nvidia's support model seems to be "unless you're spending tens of thousands of dollars, go pound sand, maybe a volunteer on our forums will help you, if anyone knows what's actually going on here."

Nvidia just has too much software, too little documentation, and holds onto their secret sauce so tightly that doing anything is a true pain.