When my daughter switched from completely breastfed to breastfed and bottlefed, we went Medela. And while she used the slow flow for the first few months, she quickly graduated the the medium flow, and at 18 months and about to be weaned off bottles totally, still uses these. They have been just right for her bottles, and they also last well. She's bitten through one of them, but that's it. In fact, they've lasted much better than the Medela bottles we bought-- after just a few months, the writing was fading and chipping off, but the nipples look like new still. I don't recommend washing them only in the dishwasher. It's a good way to disinfect them, but they tend to develop a film and need to be washed by hand afterwards. They also benefit from a bottle brush, as it can be hard to get all the way into the nipple itself with just a sponge. Overall, though, they were a great way to transition from BF to BF and Bottle Fed.