I think it is a terrible thing for charter boats. Those guys never understand how to operate one, and almost always forget to when motoring, so they end up running the engine all night at anchor. We used to have them on all the boats we chartered back in the 90's. A real PITA for someone unfamiliar with them. 12V systems just work in the background with no operator involvement at all.Sounds like engine cooling might be ideal for charter boats.
I remember having one on a boat in the virgins eons ago.
Wouldn't work for me now
Engine is often not fired for weeks..evens months
I was thinking the same thing about engine use. There are definitely weeks and months we don't use the engines, and then they are used for maybe 5min to get off an anchor. Then there are the layup times when we do some land travel where we don't want to get rid of the contents. There are even times we stay with friends in other places for a couple of days where the reefer would keep us pinned to the boat.
Just like the solar, the 12V reefer for us is a background system running without us ever thinking about it, or interacting with it in any way. Not many systems on a boat give you that freedom.
Personally, I only see an engine-driven system as being an advantage for boats that can't install sufficient solar and don't need a generator for other reasons, or boats with reefer systems so large they need the capacity an engine driven compressor can provide.