How open can an open adoption get?

We have an open adoption. I send pictures often. We text regularly. We have visits a few times a year. I'm sure it would be much more often if we lived closer to each other. But seeing how we live 7 hours apart, we can only visit a few times a year. My mother actually owns a vacation condo in the town that my ds's bparents live in, so it works out great! We even call each other our extended family. For the most part, I enjoy having an open adoption. It scared me when we first looked into adopting, but the more educated we got in adoption, the less frightened we became. We even feel that open adoption (in our case, anyway) is healthier for our ds's bparents, and will be for him as well as he gets older because he'll have a relationship with them already and will hopefully not question their love for him and their choices concerning him. I hope he won't feel that anything is missing in his life and know that he has two mommies and two daddies who love him completely. Some friends of ours who have adopted and have even taught adoption classes, told us (before we adopted our ds) that when talking with a potential birthmommy who asks about certain things that she wants that perhaps you're not sure you're comfortable with, to say that you haven't really thought about that and you and your husband will have to discuss it. But if you say this, you need to get back to her with some answer that you and your husband feel comfortable with. Because you really don't want to promise her the moon and then after the adoption renege on your promises. Start small and then build up to what you're comfortable with.