The side lace up tramps probably offer less wind resistance, due to an open space that allows the wind that gets under the tramp to pass through the boat when healing. I dont think that is the intent, I think the side lace up tramps were done more as a better way of attaching the tramp to the hulls.

Personally I've had lace up tramps on my first Acat and my HT. Both allow for me to really get the tramp tight, which stiffens up the boat and keeps your butt from dragging in the water.

A side benefit is that its a really nice place to put your heel and push yourself off the hull when you are trapping out. Thats the reason I like them laced up vs solid.