...I also have acknowledged that there is much to like about the package. The shortcomings of my 40hp sail drive are under control now that I understand them and the only real "issue" left is the heat exchanger. With extra maintenance we can cope with that. The engine itself is pretty amazing. It start instantly, consumes no oil, leaks no oil, is easy to work on, runs well and gives all indications of lasting a very long time.

My biggest "bitch" is the lack of guidance and support from the importer Mac Boring. I was left to simply figure it out for myself. When the first sail drive bellied up literally a month out of warranty I did not even get a "sorry". The other "complaint" with Yanmar is the cost of parts. Believe me when I tell you that the parts are not inexpensive. The cone clutch in my sail drive is double what it was in 2008. I have not needed much beyond simple gaskets, impellers, hoses, fluids, filters and thermostats that I use for my insane maintenance program (if you ignore the first failed sail drive) but that stuff is uber expensive.

I would consider a new Yanmar if I had a need for a new drivetrain but I would certainly look carefully at Beta, Volvo and others before deciding.
My guess is that they are all very good.

It might be an interesting exercise to create a parts list and ask for quotes from each manufacturer to get an idea of what you are looking at in the future.
Ask about availability of the parts at the time too....
Bruce