I assume by "weird helm setup" you mean the twin helms. I've wondered how forward visibility works out with that setup. I've also wondered if all lines go to one helm station making it the primary. Don't know.

But, if it's 4 couples bigger is going to pretty much be better but amenities might be the deciding factor. Ease of sailing to me comes down to little things like getting the main up easily (power winch?), good visibility and good sailing ability. I think the bigger the cat generally the better it sails. But, like mentioned above a boat you love while on the hook is important in the BVIs.