Some people can't ever get used to them, some people take to them quickly.
At my old job, though, we deployed a crap-ton of ThinkPad X61 tablets. Which don't have touchpads to fall back on (although they did have the passive+active panels, so people could touch the screens directly...)
I got to see WHY people can't learn the TrackPoint, and how to teach them to use it properly.
The first thing to do is... on a normal TrackPoint, the driver has its own sensitivity setting, and Windows has one. Max both out. That'll keep you from holding on it for more than 3 seconds (unless you have a large screen,) so it'll never recalibrate itself while moving the pointer. (When a TrackPoint sees a continuous force for 3 seconds, it recenters on that force. Remember that, and that's why the pointer may go zooming across the screen if you rest your finger on it, then let go.)
Then, whatever you do, don't flick the thing. That doesn't give you any accuracy, that just sends the pointer across the screen in small jumps. Use a constant (but light) force, that'll be best.