How do you deal with people or parents that compares their little one to yours?

I just let them talk and say what they want. Because I know my kids and I know what I want for my kids. So I'll just let the "other people" say what they want. However, if my kids were to have heard what was being said, I would also have a chat with my kids about the comment, when we are alone. Just to reinforce my views and to make sure my kid is not negatively affected by the comments.