The ULE body takes off a huge amount of weight and the difference can be easly be found. The ULE has cocker threads and calls for getting a new barrel right off the bat. If you have a mag thread freak, you have to get a cocker thread freak in order to use this upgrade or any other back or barrel. The Ule also has verticle feed and eliminates the need for elbows and reduces those anouying elbow hits.
Highly recomend this for any mag. Believe me, the weight drops like a ton of bricks.