I LOVE THESE THINGS they are the only googles i buy and does not leak. It goes great with the Z-strap thingy.
These goggles seal wonderfully when dry but once in water, they leak from every direction. A front crawl is not possible without water streaming across one's eyes. I believe the problem is with the a) the nose strap, which is not adjustable and b) the narrow (albeit sleek) rubber that doesn't seal well around the eyes.