Because of the cut and straps, bibs are fundamentally better at keeping the pad in the right place when you ride. It's the difference between using compression around your waist to keep the pad in place and using your shoulders. Most people find a small, downward tug on the shoulders more comfortable than compression around their waist.

Other than that, fit determines comfort. I've had comfortable shorts and uncomfortable shorts. I've had comfortable bibs and uncomfortable bibs. As you get more serious about cycling, you will tend to start wearing bibs (unless you are a woman, where opinion is split between comfort and ahem... nature call accessibility; also women have wider hips compared to their waist, so the waist of their shorts don't have to be as tight as on a man's to keep the shorts in place) because bibs lack a waistband and there is something other than your hips to keep the pad in place.

The correct option for the OP is to decide whether he wants to experiment with new clothing. Try a set of bibs; see if he likes them. Or, be satisfied with shorts. It's really nobody's business but his own. Myself, I've always found the waistband annoying; I switched to bibs long ago and never looked back.