Boot time? It's not like turning a phone on and off.
Cant say that I directly recall anyone specific installing one, but I have seen some threads around the web.
Actually, it's very similar. The Android O/S can be installed on many devices. It can be optimized to get better performance, faster boot times, etc. One store that I went to, I asked them to reboot the music player so that I could see how long it took to boot up and see if the camera was available right away.
That might work if the drain isn't too much. Otherwise, I have found some tips for getting one that boots fairly quickly. Some of the 8 core units I saw were booting in the 20 second range. That's livable, especially if they return to the last state. The last thing I last thing I want to do is to screw around with it while I'm driving. Although it looks like they use Android Auto.
I was really hoping to find a few people using them and get their impressions. Guess I'll have to be my own guinea pig.