Opinions of Mikelsons and similar boats...

As I followed this thread, I see you are in S California….. you may want to check around and find out about slip availability. We had a 30 foot boat at Dana Point and moved up to a 43 Mikelson. Dana Point has a ten year wait for slips at that length. We had to go North to Cabrillo to find a slip.
If you see a 43 Riviera you might check it out. They have two cabin two head design. Some of them have two bunks side by side in the guest berth rather than bunk beds. Rivieras are made in Australia and well built. Only downside is they are European voltage for coffee makers etc.
Berthing will still be a problem. Mikelsons have V drives so the engines are under the cockpit and not under the floor of the salon. Very easy access to everything on and around the engines, generator. Etc. Less noise. diesel smell, etc.
Detroit’s are pretty old and finding new mechanics that are knowledgeable is getting harder. Cats are pretty common. Good luck in your quest.

Congratulations on getting into escrow — that’s an exciting step. You’re right to weigh the pros and cons carefully, especially when comparing Cummins-powered Mikelsons to older Detroits.
The 450 Diamonds with documented maintenance and 1400 hrs are usually seen as reliable, efficient, and more appealing for resale than the 2-cycle Detroits, which (as you’ve noted) can be costly to run and harder to move on later. The Northern Lights genset with matching hours is another strong point.
The Hatteras you mention sounds like a beauty in terms of refit, but the unknown hours on 892s could be the biggest risk factor — especially if you want a worry-free experience with your daughter aboard. Repowers or major overhauls on those can easily outpace the entry price of the boat.
I tend to advise clients and contacts that, for family use and long-term enjoyment, going with the newest platform you can comfortably afford usually saves money and stress down the line. It’s not just about engines — systems, wiring, and layout on newer boats are typically more family-friendly and lower maintenance.
In my work as an intermediary on yacht and luxury asset opportunities, I see often how the right choice upfront can prevent costly headaches later. Trust your instincts and your surveyor — and make sure you budget for the surprises that always come up. Sounds like a lot of great memories are waiting to be made either way.

You guys realize this is a 15 year old thread, don’t you?

by now I do hope the OP is out of escrow and has moved to the top of the 10 year slip waitlist