I tried the Gecko CF climbers today. I'll say that they are unbelievably light. They definitely do not work with my 16" Climber boots. The top of the boot is midway on the pad and thus digs into my shin. I rolled my boot down below the pad and the Geckos were super comfortable...I just had to get the boot out of the way. I have other shorter boots that I will try next time, but yeah, not good with the 16 inchers. The Gecko CF were so light and comfortable and didn't clank or rattle as they are all one piece. The upper velcro strap was quite adjustable and made getting in and out of them really fast. It will still take some getting used to... as it is a different geometry and feel than what I am used to. There are a lot of things I love about them, and I hope the slight negatives/differences will all disappear as I get used to the new feel.