Posted by Tim: TKP62@aol.com
I’ll chime in here as I have been doing a lot of research to upgrade my A/H. This is all Raymarine info, as I have no experience or knowledge on Furuno units.
I have a 1999 C380 with (factory?) installed ST6000 and a Type I linear drive (electric ball-screw type ram drive) mounted under the transom step and connected to an Edson arm (this part is readily available from Edson, and is specifically designed for linear drive units).
The ST6000 is an old unit with no other unit other than the control head, where all electrical connections are made. It does not handle heavy seas very well at all, and forget quartering seas. It will steer to a waypoint (if properly connected to a GPS), or a wind angle, as well as a simple compass course. It is a basic A/H.
The last (now retired)