Based on my aerodynamic expirience, I would think that closed edges are far less dragy than laces. Also I think that the extra lift is something good, as it reduces the needed displacement. Finally it makes your main more efficient, not much, but a bit. All effects are certainly small, and if there are any benefits for a laced layout as better control in strong wind or faster trapezing, than go for it.

Cheers,

Klaus