I own a few of these cups from buying at Walmart. Only have one with the freezer gel, which I enjoy. Keeps the first drink cold for a while but it thaws after about an hour. Also, as long as you screw the top on correctly, theyre fairly spill proof (except for the small hole where the straw goes in, but I've prevented a lot of major spills with the screw on top). I haven't dishwashed them before. I dropped one without the freezer gel once and it broke fairly easily (the double wall came apart). For the price I would definitely recommend these. Great for keeping drinks cool at outdoor parties and such.