I ahve found the Vertex to be the best smoothest and longest lasting.I have turned a few click pens in my time and to be honest most of them were crap so I stopped turning them the last one I done was the sierra and the button broke on half of them within a few weeks 8mm click pens half of them never worked from day one and that is why I dont turn them any-more however I have heard from a very reliable pen turner the Vertex is the best ever
I ahve found the Vertex to be the best smoothest and longest lasting.
Having said that I made a curly clip one piece click for My Drain and she just loves it and uses it daily without issue
Charlotte found the curly kits and made them all up to her delight, they seem to be ok too.
Other than that I have not liked any either.