I have been really hapy with my intuos from wacom. Try applications like the free Sculpty or the Zbrush evaluation when you are testing, then you will see the really nice points about tilt sensors, and pressure.
Zbrush sculpting is as close as I have ever come to actually felling like I am touching an object that I am working on. The next closes thing would be to actually model something in clay with my hands.
I had the Cinitique for a few weeks before it blacked out on me and I was able to return it for a refund.
I was not really impressed with the lag, Another thing is the constant need to clean the screen. No matter how much you wash your hands the human body produces oil. There is no stopping it. So If I like working without surgical gloves on, I was washing the thing off at least once a day.
One last +1 for wacom... If you ever decide to try Linux the drivers are really good.
TL;DR : 3D sculpting is a great way to judge the usefulness of certain features.