For us there are two other things: portion control and storage. We don’t eat enough potatoes to have a bag sitting around, and we don’t always plan far enough in advance that we have a few potatoes when we want them. The refrigerated packs last a few weeks, so the “potato urge” can be indulged without a separate trip to the store, and a small pack serves 2, the large pack serves 4.
Wegman’s has a brand that is really stellar; they have Yukon Gold mashed, redskins, and others. I can’t think of the brand name, but they are pretty good.