"I bought two of these for my daughter (age 4). She likes them very much, the fancy straw is a big hit with her and she likes the color purple.
They bricks in the base of the cup, lead to some confusion as my daughter wanted to play with them, however they are part of the cup and will not come out without destroying the cup (I'm not willing to do that). We've moved past this.
The cups are easy to clean, but the straw isn't. It tends to trap fluid and you must take extra care to clean it. This problem is shared with any fancy straw, not matter the source. The straw does come off, making life a bit easier, but my daughter always wants to use the straw.