I want to purchase to follow focus having precise focus control. Which follow focus you are using?

Does anyone have any experience with the following follow focus?

Camtree ?url= http://www.proaimshop.com/pas/CAMTREE-Solid-Gear-Follow-Focus.html?solid ?/url?gear follow focus
Proaim ?url= http://www.proaimshop.com/pas/PROAIM-V2-DSLR-Follow-Focus.html?V2 ?/url?follow focus

What you think about these follow focus?
Which one is good?

Thanks

Cinematography