I run it on a raspberry pi 3B+ with a SEEED 2 mic hat. I am very impressed and recommend it to anyone with an interest in offline voice.

I have also tried the server/satellite approach but found that standalone devices worked better for my purposes.

Unfortunately Mycroft has been discontinued by its management team and is heading towards deprecation. This project is starting up now and has a strong initial release that works well. Mycroft was intended to be used with a cloud backend hosted by the Mycroft team (that being said they did eventually open source their backend but it was not intended for use with single instances).

Willow is designed to work with very low power/cost hardware (esp32-s3-box) and either homeassistant or openHAB right out of the box.