One of the biggest advantages I've found of the newer style BD tip loops is there's no fold (ie double layer of skin material) proping up the skin away from your base and allowing for snow to pack in there and pry things apart over the course of a tour. The BD tip loops let the skin sits more flush with the ski base. I've noticed less snow packing in as a result. You also save some weight as less material is employed.
The K2 skin tip loops are my favorite (most compact and protected from opposite ski edge) but require a tip hole on your skis if you don't already have one.
