I wanted to give you guys a durability update.
I have been using mine every day and trying to use it instead of the waterfall ones.
I have been using it a lot with the cell phone holder pictured and with a coffee tumbler.
It hasn't shown any signs of breaking. However, it has deformed slightly. Notice in the image the piece is no longer a perfect circle. It still works but it isn't as smooth as it was originally. Now I really need to use the "pinch technique" after placing something large in it.
I put another one in to try and see how I made it deform. It seems that if I place something large in the cup holder it forces some deformation in the piece due to weight and/or over opening the mechanism. Then, unless the cup holder is closed, it stays in a bind in the deformed form even when the weight is removed. Since I haven't closed my cup holder in a couple weeks the shape seems to have stuck.
I took a heat gun to mine and fixed it, but wanted to let you guys know that heavy things like a 30oz tumbler, or things that lean back and put weight only on the new piece like my super top heavy cell phone holder, seem to cause it to bow. That alone doesn't seem to be an issue as long as you don't leave it that way for an extended period of time, but it eventually did cause mine to drag when shutting the holder.