They both are the same except for the block that fits into the vang key and the double block that comes with it. The more expensive one comes with a slightly better quality line as well. I have the less expensive one and I find that it works fine. I wouldn't pay a extra 70+ dollars for the slight difference.
The more expensive kit has more expensive blocks, lines and cleat. I wouldn't expect it to work measurably better.
The "new" cleating fittings were designed to be rigged as 15:1 (3 x 5). If you want some other ratio (12:1 is gaining some popularity), you want to get blocks and line lengths that are slightly different from those in the kits.