This is my daughter's favorite sippy lid. She doesn't like to lift the bottle back to drink with other types of lids, so this one with the straw is perfect for her. The flow also seems just right.
I am on the fence about the transitional sippy lid with straw. We like all of the Olababy products we have, including the bowl and spoons, and the bottle with the offset nipple and the “soft spout” when my child was younger, but he is 17 mo old now and he is squeezing the silicone bottle, so this straw lid leaks his milk or other drinks quite easily. He is a bit rambunctious, so maybe a more mellow child or one who does not like messes would do better with this lid. It does fit well with the bottle and when I tried it myself, it works very well. However, once my child figured out he could basically “blow bubbles” in his milk by squeezing the bottle, or can toss it on the ground and a little bit of milk spurts out, it kind of became a fun game, not much milk drinking after that. I will keep the one I opened but I will probably return the other two and will continue to use the regular Olababy soft spout lids as he works on drinking from an open cup.