I'm not sure how fast your legs sink Jeff. For me it's like what Pantoja said. I like enough weight on to have an easy descent. I feel that more energy is expended when breaking the surface than throughout the whole dive. It is at the very beginning of the descent when I know if I'm going to have a good dive or not. So I like to have enough weight on to facilitate breaking the surface. It may go against conventional safety procedures but I float vertically, with the top of my head just on the surface, with my lungs full. When I exhale about half of my air I start to sink slowly.
This goes with what Pantoja said. During breathup in order to relax I put emphasis on a long exhale, to clear the lungs for the next breath. As I do this I start to sink so I must kick a little to stay horizontal. Ideally to relax you don't want to kick too much. Evidence of this is trying to breath up in current while swimming or even maintaining position, it's almost impossible to breath up properly in those conditions. So breathing up is a balance of relaxing and at the same time doing some minimal kicking to stay in position.
When I think about all this now I'm tempted to experiment with less weight. This theoretically will make less kicking necessary to stay horizontal on the surface and should facilitate breathup. However I suspect that as the weight belt is located on the lower portion of the body the legs will sink first regardless if all of you doesn't end up sinking and so kicking will still be necessary. Honestly I don't pay attention any more to kicking while breathing up. I am however looking forward to losing weight. Then I will require less weight on the belt and be better balanced overall.