Bill,

I had a "conventional" 3 piece trampoline - with center / back lacings. The two piece is only available in solid vinyl (I think), which I would never go back to. I really don't like sitting in a puddle.

I like having the lacings - the back lacings give you a place to jam your heel in when sitting on the wing, and the center lacings give you a place to grab when hauling yourself from one side to the other in a tack.

At 230, your son is a big guy to be sailing the 17. He's going to be spotting some people (like Dan Ward) about 70 lbs. Look out when the wind blows, though!