This is my second Contigo. It works wonders, it really does keep your beverage warm. They only annoyance is you have to slide the button every time you want to drink.
My wife has difficulty screwing the top on, but I don’t. I can see how some may find trouble in getting it on properly though. The lid does seal nicely and is truly spill proof once locked. The button is kind of hard to flip while holding with one hand. I think with time it’ll loosen up and break in.