I'm a recent user of PI. I have spent loads of time looking at videos (thanks Harry), playing with images, checking out the various modules and so on. What I like is that it's all interesting and engrossing--hard to tear myself away. This was never something I experienced with Photoshop, where techniques were boring things to be learned only as a means to an end. As a mathematician I really like the detailed descriptions of the various processes--it's nice to understand what's going on. It's a pity that the documentation is lacking for many of these, but hopefully this will change as time moves on.
Geoff
