It all comes down to the quality of the installation. the number one cause of insulation failure and condensation is of the insulation is squeezed up. On the Lazzara I ve had two places where it happened. One was in the ER under a cover above the chiller rack. Easy fix... took out the small cover. Who cares if a couple of pipes are visible in an ER. Second has been in the ceiling in the smaller of the crew cabin where space was tight and the ceiling panel crushed the insulation. Easy fix. all the piping is heavy duty PVC and I think the last time I used the valve to raise pressure in the system was two year ago... as to the circulation pump being a failure point, true. But just like the sea water pump, we carry a spare. Actually I replaced the pump last month, it was 10 years old and started to make a little noise. It wouldn’t be hard to have both circulation and sea water pumps doubled up so you d have a back up ready to go at a flick of a switch and valve... not worth it as long as whoever is on board can change the pump. If installed correctly each air handler can be isolated with valves of one fails. A must with crap’air air handlers so you can replace them without shutting down the system In all these years, I ve never had an issue needing cooling and heating at the same time, even up north. That’s a compromise I can live with The 2 chillers and 5 air handlers for my 53 weren’t cheap... about $20k plus the hoses, insulation etc. i installed it myself And it s probably the best money I ve spent on the boat besides the repower.