The Control Tech isn't cheap, but it's solid and works well. It's a super simple design, too, and relatively easy to work on and set up. On the plus side, the workmanship is very good. Also, the posts come in a few sizes that, at least for us, eliminated the need to use seat tube shims. However, there are many drawbacks.
Suspension travel is minimal.
I get about 0.75 inch of sag and 0.25 inch of actual suspension travel. These posts do not use a rubber dust boot. Instead, there is a hard plastic outer tube that covers the internals and slides up and down with the suspension action. My 27.2 post is badly gouged by dirt that gets trapped by the boot. Another drawback is weight.