Pros: They collapse very well and are stable because they have good support on the bottom.Cons: they are not insulated, so the middle part will get hot with hot liquids.Other reviews talked about the initial smell. When I first got them I washed them with hot water and soap and let them soak. No smell after that at all.We ordered these cups to use at work or camping. We were surprised at the quality of the silicone. The silicone is thicker and sturdy, not flimsy at all which allows you to hold the cup without it collapsing under your grip. However don’t try holding it too tight. The plastic lids was a little difficult to un-do the first time but once we got it off, it was easier the subsequent times. In all we are happy with this product.Looks as described. Leaks a very small amount at the seam around top of the cup. Even with the top on. Ok if you drink with a straw. Otherwise ok with purchase.Bought to carry in my purse but haven't used them yet due to covid-19. I love that they collapse and can still hold a decent volume. I hate using single use plastics and these will be perfect!I thought I’d love these, but the drinking hole is so far from the rim, it’s impossible to drink with the lid on. Getting the lid off (and back on) is another challenge. I still like the concept, and maybe the smaller sized cups would be better, but this size is unusable.I got this as a Christmas gift. And was extremely excited about using it, since my reusable coffee cups always take up so much space. I poured my first cup of coffee inside, but no matter how much I tried, the lid would not go on correctly. It proceeded to leaking all of myself as I was driving. I am very disappointed, as I was really looking forward to getting another one if this one worked out. I've tried a couple other times, but it always leaks hot liquid.