Are you a people person and can let all the "issues" that come up between people slide away? If so, bring an ipod with music you like and prepare to have a great time. The crew is great, the boat has everything you need and nothing you don't and the water is darn near perfect.
If you want to go with your husband/wife/significant other and "be together" this is not the trip for you. There is no privacy and no "away" at all on the boat.
I've been twice and going a third time this summer. Friends I met on the first trip (in the middle of a tropical storm nonetheless) are my same buddies this trip because we had a great time together and know each others habits at this point. I would suggest trip insurance though, I chanced it twice and came out ahead, but last time we got in the day after a hurricane. That was cutting it all WAY too close for comfort, nothing like literally watching the news reports to see where the storm was RIGHT NOW to see if the plane could go to the bahamas. A couple bucks in insurance could help out dramatically in the long run.