Like everything else on a boat, I want them to do double duty

So I'm down to one choice...

We very rarely use both engines - pretty much only for maneuvering in tight spaces or anchoring. We reach 6kts using one, and only gain a little more with both while using a lot more fuel. And time between maintenance is doubled, although I have to work on two engines when it is time to change oil, etc. So it really is like carrying around a spare engine. I can't think of a single common failure point on them other than completely running out of fuel - separate fuel systems, separate electrical systems, separate control systems, separate gear boxes. Most cat owners I talk with also operate this way.

I share your opinion about Raymarine and don't consider them a robust choice for autopilots. However, they have not bought out the other AP companies. I assure you that Navico (Simrad and B&G), Garmin, Furuno, NKE, WH, Alpha, and many others are separate entities (and better choices).

Mark