It's the NAC 3, using a AP44 or the NSS9 EVO3. The compass is a rate compass. All this sh*t cost a lot of money.
The Autopilot controls (and their descriptors) are:
Turn Rate - Target rate of turn used for heading change
Rudder Gain - Ratio between heading error and rudder command
Counter Rudder (secs) - Counteracts the effect of turn rate and inertia
Autotrim - Corrects for static heading error induced by environmental forces
... and a few more that don't have relevance
Coming back from Barrier yesterday I was fiddling with the Rudder Gain. Originally it was set to 0.25, this seemed to just add a bit of helm when we were off course. It didn't keep adding rudder to try and correct it, it just seemed to go "ah F$#k it" and error. I changed that to 3.0 and that was better, but very very busy. I dropped it back to 0.5 and it seemed closer to where it should work.
What is annoying is that you just want the fecking thing to work. Trying to understand the manual/instructions is a challenge in itself. "Ratio between heading error and rudder command" is all well and good but it doesn't actually tell you how to use it - as in "set to a larger number in heavy seas". As for the Counter Rudder setting in seconds, who knows what that is going to do. All in all I'm a bit disappointed with all the "latest and greatest" crap I've bought. The NSS9 EVO3 can run a FLIR camera, which is really fantastic for some people - except if you want to GoTo a waypoint - you can't, you have to go Find/Waypoint/select/GoTo. I've used systems 20 years ago that were better.....
Hey and thanks to all for your input!