I don't drink the Atkins shakes, I use EAS Carb Control shakes and love them. I usually grab one in the morning for breakfast (not good, but better than nothing). And sometimes will have one at night if I'm hungry or if I need to get my calories up. For breakfast, I combine the shake with heavy cream or sour cream and flaxseed.

Most don't use shakes even on Induction, but I've not had a problem. Without the shakes I'd go without breakfast most days, and I think that's worse than the shake.