My shorts don't slip down on me, but being that I'm still circumferentially "enhanced" (even if only mildly so after my weight loss to date), I tend to have a problem with waistband rollover, which is highly annoying, especially on long rides. Bibs solve that for me completely. I still have my shorts, including some very nice ones, and I wear them from time to time, but all other things being equal, I prefer the bibs.