I have a mycroft mark1. It is based on the rasberry pi, and as they are wont to do the SD gave out (or got corrupted in a power outage?) and I haven't tried to fix it after a couple years. It works, but it is tricky to get it to wake up, you have to be close to it and speak up, no using it across the room. It is a neat trick, but I never found a use for it that was worth making it work.

I backed the mark2 on kickstarter which they have been promising is better and will ship anytime now - for a few years...