We were on the Nekton Pilot in Belize a little over a year ago and loved it so much that we're booked for 2 weeks this summer on the NW Bahamas and Cay Sal Banks itineraries. Last I heard, the NW Bahamas week was only 1/2 full and the Cay Sal one was nearly full.
I've read a lot of trip reviews about both itineraries and it seems like about 50% of the reports I've read include comments about current at one or more of the dive sites in the Bahamas, so that's something to take into consideration. Since it isn't something anyone can control or predict, I'd rather risk having current at a fabulous site than no current at a yucky site. But that's just my personal preference.
The Pilot recently spent around 6 weeks in drydock being spiffed up, which I have confidence addressed some of the cosmetic problems she was having.
The one thing that is very obvious when you've been on the boat for a day is that it is a working dive boat. It's not a cruise ship or a yacht and it doesn't try to be. But you'll have a large cabin (by liveaboard standards), a private ensuite bathroom, lots of room to move around, a smooth ride, good food, an outstanding crew (IMO), and lots of fun.
Not one liveaboard (or dive op) will satisfy everyone, so it's a matter of figuring out which one meets your needs. Nekton meets our needs perfectly as we have the space and privacy we want as well as a good price, but to say they are for everyone is silly. Do your research and pick the one that fits you best...you won't likely go wrong that way.