If you ascend the rope srt during removals, get kks. If you do not, good chance either will do much much better than bucks. Kks are made by a small one-man company and have gone through to a 4th iteration in development. They are designed by an arborist in consultation with a prostheticist (is that a word?). I know nothing about gecko development, but generally hear great reviews about them. One taller climber did not like his geckos - they were too short to adjust. I expect my kks to arrive as soon as the spikes are fabricated. There is a kk website. Kk is also on IG and Facebook, and, I hear, gofundme. If you are not tire-kicking and intend to buy, I'll forward the kk email address by PM. Hard to go wrong with either unless you ascend the rope srt during removals. The geckos require intervention to install a spikescender. Hth