My scroll wheel was very stiff and irritating at first. It did loosen over time and is now completely useable. It doesn't free-spin, but it also doesn't take a lot of force to move.
The lack of clicking is a little disconcerting, but not a deal-breaker for me. I guess you could add an extra part to make it click — like putting a playing card in the spokes of a bicycle wheel.
Because I bought the trackball mouse, I changed the trackball to scroll when a button is held. I now have horizontal and vertical scrolling, and don't use the scroll wheel except for middle clicking.
