I have heard good things about One-up's V2 ($200) reliability. I have a bontrager line elite dropper which is functionally identical. I had issues with seat wobble but disassembly was a breeze and it turned out that by flipping the keys, I was able to reduce the wobble to "acceptable" levels. The only other issue I faced was that it is occasionally stiff at the first drop. Once through this initial "stiction", it's smooth and easy. I imagine that it will get smoother with break-in, and the keys are like $4 if I decide to replace them.