I am currently on my Lagoon 42, Sea Tiger. which is also in TMM fleet.
Look for extras: A few boats in TMM have Watermakers... Very nice feature as we are 10 days into our trip and have not docked ANY for water... And crew is not in the water conserving mindset. (Having to stop for water can affect itinerary, as well as delaying for dock to open or waiting for others to leave dock. Just a couple of weeks ago, North Sound was without water, thus severely affecting those planning to sail to Anegada and needing a top off.)
And yes, TMM maintenance on the boats makes them the hands down choice.
One "draw back" of the Owner's Version(3 cabin) is that the owner's hull is so disproportionately bigger than either other stateroom, then the other guests may resent it. Just have a upfront method to dealing with this issue: Upon organizing trip "cabin assignment in order of commitment to trip (ie deposit received)" or lottery.
In the spirit of full disclosure: I know Deepcut and Sea Tiger well, crewed the delivery of Sea Tiger from Ft. Lauderdale to Tortola. Deepcut and I, along with many other TMM owners, communicate often about our boats.
I agree that a watermaker is a very nice option, and we are looking into installing a watermaker on Ocean Song.
I also agree that TMM's boat maintenance is the best in the BVI - hands down.
However, I have to push back strongly about the owner's hull of the 3-cabin version being a "draw back". I think it's the primary reason many charterers prefer the 3-cabin version. We have had many families charter Ocean Song and the spacious master suite is a great feature, providing a degree of privacy and luxury for Mom and Dad one simply cannot get on a 4-cabin catamaran in the 40 - 50 foot range. Charterers are astonished by the open, airy feel, the storage, and added comfort as compared to the 4-cabin versions.The much larger and more functional owner's head and shower receive rave reviews. More and more charterers are now asking specifically for owner's versions.
We have also found that couples chartering Ocean Song have much preferred the 3 cabin layout to their previous charters on boats with 4 cabins. As long as the charter group (not including professional skipper) is six or fewer, the owner's version is the way to go. I think any group chartering an owners version has worked out who gets the master suite well in advance. We understand the master suite to often be the "reward" for the charter organizers. Each time fellow sailors, charterers, and catamaran owners of 4-cabin models come aboard Ocean Song they express their jealousy of our master suite. They have nothing on their boats that can be called "suites", the 4-cabin models have cabins and heads. No one has indicated that it has been a draw back, except that it draws charters back for another charter on an owner's version!
We specifically wanted an owner's version because we plan to live aboard in the future. Also, we felt it would attract more families and provide a level of comfort the 4-cabin version can't match. To date, we have been proven correct.