In case I'm one of the "tainted" owners I will state up front on the very first sentence that I'm a boat owner at CYOA.

Before being a boat owner I chartered both in BVI and then later out of St Thomas so I have experienced both. I obviously prefer St Thomas - many reasons for this. However - I think it would be silly of me to believe that you necessarily value the same things that I value. You indicate you have already chartered multiple times out of Tortola so you know what that's like. Give it a try out of St Thomas and compare the experience - I don't see how you possibly have anything to loose and you might find you like it. I did.