I got a Shield TV Pro 2019 off Amazon.com in December.
It's very buggy compared to my Roku / Fire TV & clearly they don't have the capability to do extensive QA testing like the competitors.
Although the CEC control works for everything else (Turn on, turn off etc.), it does not work for the volume control. I have to turn on IR mode to control the volume. It works on the other devices out of the box.
Firstly, it's not really compatible with my Samsung Smart TV like the other brands are (something wrong with the colors despite trying all the settings).
Holding the volume buttons to change volume is buggy (the increments are very slow). This is a known bug that they promised an update for months ago, but have yet to release even via their manual hotfixes.
After a while, the remote started to drain batteries like crazy (1-2 weeks for a battery change). Their troubleshooting & resets did not work.