I loved these bottle when my daughter was first born, however, after using them for about 8 weeks, I ended up hating them. These leak. I know I've seen the same comment in other reviews but seriously, it's a huge problem. A bottle leaking out of the bottom is not okay when you are trying to feed your baby. You can't set the bottle down at all after you've made the milk (we formula fed) and we had to keep a finger on the nipple to prevent it from leaking out that side when we were walking from the kitchen to whereever we fed her. And really the nipple leaking was a lot less than the bottom. I also don't know that the venting was all that better than some of the other bottles out there. There are a lot of parts to clean, but that really didn't bother me too much, as long as they worked. Also, the wide nipple was okay to begin with, but my daughter had a hard time latching once she got a little bigger which meant a lot of clothing changes after she ate so she wouldn't have to be in a wet onsie. I think the concept of these are great, but it really needs some improvement if it wants to become a "goto" mommy product.