I've been using these bottles (wide neck, skinny neck,) with my baby since she was a few weeks old and love them. I've been trying to see if she can handle the "Options" bottle without the vent (I'm tired of cleaning the extra pieces and she is handling it well). However, she still uses a size 1 nipples and the nipple continues to collapse as she drinks. Does anyone have this issue? I want to move her onto a bottle with less parts, but don't know if I should buy a different size nipple, or a whole different bottle. Let me know if you've experienced this! Thanks!!