thicker, more detailed back, smaller waist, way better arms, better quad sweep, thicker chest.
At his best, Jay has a really thick back, but the same problem Mike had - not a very conditioned lower back. They both had good Xmas trees though. Also, Jay is way wider and his outer quad sweep probably seems better than mike's due to their taper. Mike had no taper in his quads - they were as wide at the bottom as they were at the top. But he was better conditioned than Jay though - looked liked he was carved outta stone in the 95 Arnold classic (that he won) a la Dorian