Help me decide with my First Cup

help me decide! I want to buy my first Stanley. preferably pink and glitter. I live in Germany and have now found both of them. the pink one in 40 oz and barbie is only available in 30 oz. I currently have a 25 oz AIRUP bottle at work because I don't drink much. That's why I think the 30 oz is enough, but I think i like the look of the 40 oz one more. what do you say??? Thank you 🥰