We were on the T&C Aggressor in the fall of 2013 and we had a great time; the boat and crew were terrific and the diving was superb. Beautiful walls, lots of healthy corals and sea life and many large animals, including sharks on just about every dive. We also did a Peter Hughes Dancer livaboard out of Provo many years ago and it was a great trip, too.
We have not been on the T&C Explorer but we did an Explorer trip to St. Kitts and Saba and it was excellent. So I would be very willing to dive with them again, too.
I think that the pricing for the T&C Aggressor and Explorer are approximately the same amount. I've read on this board that the Aggressor rate seems a little higher but it includes some extras like taxes or surcharges that are added later to the Explorer's price. But both operations run specials during the year so I would probably look for the best total cost if I was trying to decide between the two boats.
Do try and spend some time on Provo and Grace Bay; it's a lovely place to visit. BTW, the T&C islands are very expensive so a liveaboard gives you the best bargain for your cost per dive as compared to a land-based dive operation and you avoid long rides out to the best dive sites.
If you do spend more than a couple of days on shore, I suggest getting a kitchenette or an apartment so you can prepare some simple meals and get a rental car because taxi rides are costly; have fun!