Absolutely life changing.
My daughter is prone to high temperatures and doesn’t easily drink anything outside of milk in a bottle. We tried every bottle and cup under the sun to get her to drink, with no consistent answer. Until the Tippy Up Sippy Cup with Weighted Straw! These are so amazing I’ve bought them for friends with younger babies to help them wean successfully. As for my own daughter, she happily drinks from her “bear cup” all day long and stays hydrated (and * touch wood * we haven’t had a high temp since). We own Boris (blue) and Betsy (pink) who are used daily. Worth every single penny.