I don't know about low carb, but I like Quest bars. They aren't cheap. I mainly get them at GNC because I am a member and benefit from buying them when they are on sale. They are the cleanest bar out there and they taste WONDERFUL and they don't have fake stuff in them. I would rather have something real with higher carbs than fake with fake sugars and low-carb, but that's just me. To me, they are really good when you have a sweet craving. The chocolate chip cookie dough is heavenly. But, they are sweet. Sometimes I will eat a half of one and the other half later.
I also just have the VSG right now so I don't know how DSers respond to them.