I so wanted to like these, I got annoyed with all the plastic landfill.
The problems I have with them:
1) Drinking ice smoothies would conduct the cold brilliantly... making the outside too cold and wet with condesation.
2) Chipped teeth.
3) Walking and stumbling while using these... a metal rod into the back of your throat... and thoughts of my children falling while using one?
So I rarely use them, and for other times just stick with compostable plastic straws.
Not that I need straws, it's just those smoothies and my beard... don't mix.