Just got back last night from the T&C Aggressor. It is a VERY nice boat. You might have heard though, that it was run aground during a freak storm and we had to abandon ship. Luckily, it was taken off the reef and all gear and camera equipment were safe and sound. It should be back in the water this week, but will have to dry dock soon to take care of some repairs. Piers (the captain) is the best, most involved captain I have run across in 11 or so liveaboards. The crew is generally very very good as well. If you are a photographer, itis by far and without a doubt the best boat I have been on from a photographer's perspective. All but two of the cre are photo/video folks (Aquatica freindly), and the cap is a fantastic photographer. On board desktop with photoshop and CD burner. Can NOT beat that.
The Explorer assisted with the rescue, and afterwards docked next to the Aggressor. THe Explorer is MUCH bigger, we got a short tour from Francois, that capt (?) and it looked very very nice as well. From a boat perspective, you couldn't go wrong with either. I am partial to the Aggressor crew, though, for getting us out of what was a very hairy situation.
Did the CEII in Saba in Dec, 2004, and the boats are incomparable. I was not too impressed with the CEII or the crew (or the diving).
Chris