I still wear shorts, even though everyone I know wears bibs. The main reason I stay with the shorts is they make it easy to pee, and I go often. As far as the elastic around the tummy thing, I just roll down the shorts and wear them low. Bibs are also a lot more expensive, here anyhow. With Summer being +30º/86F everyday I don't want anything adding unnecessary heat to my body.
CHEERS.
Mark