Is a Custom Double Wall Tumbler Really Worth It?

I saw someone using a custom double wall tumbler, and it made me wonder if it’s actually better than a regular cup. Does a custom double wall tumbler really keep drinks hot or cold for a long time, or is it just cool because you can add your name or design? Some people say it’s perfect for school and trips, while others think it’s too bulky. If you had a custom double wall tumbler, would it be super useful or just something fun to show off? I’m curious!