i have a yeti 30 oz cup kids gave me for christmas. i love it, keeps ice all day long. wanted another, but didn't like the $40. heard wally world was selling a 10 dollar knock off, finally found one in stock, so i tried it.
i filled both cups with ice and set them on the back porch. left them out overnight for 15 hours. got up next morning and drained water for comparison. not 100% scientific, but close enough for drink cups.
as you can see, pretty close to same melt rate.
just thought i'd share this
the yeti is silver & ozark is black