Hi there,
We did a lot of work on our Mainship 430 aft cabin, and it's a good boat with easy access to pretty much everything, including the engines, which explains why they are so popular.
I love the solid fiberglass hull and the deep keel, which protects the props and rudders and makes the boat more stable at the trawler's speed.
The boat is heavy (36000 LB on the travel lift last year) and super stable. My wife was susceptible to even small boat movements which made her seasick even in the marinas in all our previous boats before Mainship. We had a few long trips on the Mainship, and she was surprisingly fine in all the conditions we experienced.
I think, Swift Trawler 41, and probably Sabreliner, have a cored hull with balsa sandwiched inside - not my favorite construction. it will get wet, just a matter of time. They are great when new, but at $300k you are probably looking at least 15+ years old boats, and there will be wet balsa in the hull.
Also, this made the boat lighter. It's good for an extra 2-3 knots of top speed but bad for stability at the anchor and in the slip.
If you want to consider a Mainship, we are putting ours on sale this spring.
The boat is currently in Woodbridge, VA, and we are moving her to Colonial Beach, VA, in April.
Here is my "for sale" post with more details:
For sale: 2002 Mainship 430 (refit in 2022-2025)