Rich,
The condensation pan on my old Mermaid corroded out and leaked water. Eventually, unit stopped cooling...
The unit was replaced with a Dometic DTG16 Reverse Cycle Heat Pump With Smart Start. This version has a composite pan - no rusting. The control panel also had to be replaced.  After a year, both heating and cooling are very good. 
BUT, I was hoping my Honda Generator 2000 series would support powering the Dometic at anchor with the Smart Start. Technician at Dometic stated 40 amps are required for a milli-second, and the 30 amp rated generator will not power the compressor on. If anyone has a work around for this please post.

Rich, the new unit is a "bit" quieter. The fan speed can be adjusted as well, but only helps a "bit". Dometic offers a sound insulator cover for some models. But the heat or cool air when needed, more than makes up for the noise of the unit...

https://www.dometic.com/en-us/outdoor/boat/marine-air-conditioners/marin...

Rob,
I assume you are in Ontario,  I was always with the impression that your region was relatively cool.   I never considered AC for my Catalina 36 however if in the islands or keys perhaps yes but then the dilemma would be he Generator, would want a Diesel 3 or 4K watt gen that would have be be very quiet, like you would see in the newer production boats like the Beneteau 46 etc.