I have been eating a Quest bar for lunch for a year now (to save time and leave work half an hour earlier). I'm happy with them. They are quite filling (I don't get hungry until dinner time), I like the taste of most variants (bit of an acquired taste, they do have the artificial tinge of all artificial sweeteners), and I have zero gastro issues from them.

They are a bit hard, but filling. I microwave my chocolate chip ones to make a cookie.