I used a Thinkpad with trackpoint for a couple of years in the late 1990s and found the same thing. Very quick and easy to use, but I never quite found a way to use it that wasn't at least slightly uncomfortable. The main thing I remember was the unpleasant sensation of fingertip moving separately from nail - I have the same problem pushing my fingertips along sticky or grippy surfaces - so I was in the habit of pressing quite hard, to ensure they moved as one. And that proved quite stressful on my fingers.

Eventually the rubber nubbin wore away (probably not unrelated...) and that made it even worse.

These days I've been pretty happy with the Macbook Pro touchpad. Not to all tastes, but I found it easy to get used to, and it requires only a light touch. Pretty much every other touchpad I've used has been pretty crappy, though...