Tried both the "Matin" version Attiny85 on rate mode and swapped it out for a HK401b I found in a corner box somewhere.
The latter has heading hold ability and both gyros seem to behave ok.
Did not use heading hold with the Attiny unit though after reading Pete's replies.
Call me inexperienced or whatever but for some reason I don't see a lot of difference between heading and rate mode on the HK401 at least.
Maybe it's just that the HK450 chopper is a twitchy little piece of gear to begin with.
