We have an XS-600 as a dive boat with a 115.
Its a good enough boat and very good value for money. Overall build is good and handles well on the water.
On the downside:
The centre of gravity is high and it can rock from one tube to the other when at a stand still and when people move about the deck. There is also a lack of thought by the fitters when you look how throttle cables etc run, too many tight bends for those types of cable which means the cables will need replacing after a year or so. Interesting it was the same on my Tornado ....!! Same fitters.
I have used Destroyer and XS alot and my money would go to the XS. BMC provide good support during and after the purchase which counts for a lot these days.
My advice for a dive boat is buy as big as you can afford! the XS-600 would be the smallest I would find useful.