What matters is the seal between the earbuds tip and the ear. A decent seal will keep them in place in most situations. I have Bose QC2 and Ultras with silicone tips that rarely have an issue because I put the right sized top on the bud.

However, they are small so easier to forget in seat back pockets etc.

I travel with over the ear cans and buds and swap depending on battery and what I'm doing at the time.