from San Diego, CA United States
I use these as general purpose glasses, but particularly when I'm in the pool area of my apartment. I've had to explain a couple of times that they aren't glass.
The silicone is thicker than you think it's going to be. They are flexible but not so much that they collapse in your hand. They're more flexible towards the top of the glass. This has advantages if you're drinking in a reclined position as you can avoid spilling on yourself by using the mouth of the glass as a funnel.
I like that I can use them for both coffee and beer.
I'm planning to send a set to a friend who has children. He gave up some time ago on having any real glassware.