Truth is, I rarely use the pen as other than a mouse replacement on my   
  concerto, but think that that alone earns its keep. The one exception,   
  perhaps, is Sketcher (or any drawing program) where the pen also makes a   
  huge difference. 
   
  My other stylus machine (a Newton) forces more extensive use of the   
  stylus, but for the most part it has just convinced me that pen input is   
  a pain.  And at that, being able to use cursive input (albeit with poor   
  recognition) proves to me that character-by-character input is never   
  going to be acceptable. Currently, most of my Newton input is via   
  Graffiti. 
   
  The times that I tried to force myself to use pen input (for note taking   
  during interviews) I used Microsoft Notebook, and thought they did quite   
  a good job.  I have tried to use both of the Inkware products, and was   
  generally unimpressed. 
   
  I too have been tempted to try os/2 - whish I could find someone who has   
  gotten it to work.  (I did find one happy user of os/2 on a concerto, but   
  he chose to work around the power management problems and felt that the   
  tradeoff was worthwhile.