I've had these for about 3 years now. After vowing to remove all "kid" cups from my cupboard, and throwing out a ton of them that were old, had too many parts, and generally not working, I found that I did need a couple for trips out and about. I read reviews and found this one highly recommended. I bought it again being unable to remember my previous objections to it. It just took one wash to be reminded all too well. This is a great cup in that it doesn't leak when tipped or shaken. It does overflow if left out in warming conditions as previous reviewers have mentioned. My big pet peeve with this product is that the lower part of the straw assembly seems to shrink over time. I wash mine in a basket in the dishwasher, so maybe that gets too hot??? All I know is that very soon after buying all of mine, they became unable to reach the bottom inch and a half of the cup. This drives my toddler crazy. She sees the remaining drink in the cup but can not get to it no matter what she does. Frustrated toddler = unhappy mom.