Hi Otter!
I'm of the same mindset in that all I want to do is sleep, eat, dive, eat dive, eat, dive, eat, dive, eat, dive, do it all over again (maybe some time in the hottub here & there). And liveaboards seem to be the most efficient way to do this. It's just so relaxing and convenient, and the crews are typically great! There is so little effort involved on liveaboard dive trips!
I did the Nekton in Belize, which I liked. I've never done land-based in Belized, so I can't really compare. I think one thing that someone mentioned about the Nekton as compared to the other liveaboard boats is that the Nekton doesn't typically do the Blue Hole. What the captain felt, and what I've read on the boards, is that the Blue Hole isn't really all that interesting from a diving standpoint. You lose a day of diving at better sites by going to the Blue Hole. They would have gone if people REALLY wanted to go, but most of us weren't all that interested. The Nekton is less expensive than the Aggressor or the Peter Hughes boat, but it also holds more passengers. I walked around the Peter Hughes boat, and it was more upscale than the Nekton. They had a beer tap on deck, which looked like fun, but I don't drink when I am doing 5 dives a day. Which reminds me that another difference is that alcohol is not included on the Nekton boats, but they always take passengers to a store to purchase their own liquor before the boat departs. I like the Nekton boats and operations so didn't feel like I needed to pay extra fancier accomodations.
I think you'd have a good experience on any of the liveaboards.
The Saturday that we go off the boat, they arranged a free trip (I think everyone ended up tipping though) to nearby Mayan Ruins before our afternoon flights. It was nice. I wouldn't have paid for it though....
Which liveaboard did you do in Palau? I've never been to Palau, but your dive expectations are probably set pretty high now....