I can’t say about the bust issue but I find aprons that crisscross in back are way more comfortable than the ones with neck loops and waist ties. I modify any aprons I buy. I can’t stand the feel of the neck loop so I cut the loop in the back center. Then I make some sort of little loop on the hip sides where the ties are attached (you can use a metal D shaped thingie or just make a fabric loop. I cut the waist ties off and attach one to each end of the cut neck loop. I cross the now longer ties and feed them through the guide loops. It helps to tie a knot in the end of the tie or attach a large bead so it won’t come out of the side guide when you are putting it on and taking it off. Then you slip your neck through and your arms through the appropriate spaces and tie it in back or all the way around. This makes the front of the apron settle comfortably and for me it seems to allow the top front to stay in place and stay centered. I think all aprons should come that way. Here are some examples
http://tinyurl.com/d7h8lvu
http://tinyurl.com/bqqmh6j
and how about this design
http://tinyurl.com/c6eqan4