Yeah I moved over from PSP too.  The main critisism I had was that photoshop is menu based and PSP was icon based.  I liked that you could put the tools that you most up on your task menu as an icon - loved that!  The other thing I miss is tubes OMG I used them all the time!  Apart from that its as everyone else says much the same - as that's from a casual users perspective I'm sure it does a lot more according to the professionals.  Once you've found your way around the menus its fine but I found I had to break from PSP all together so that I wouldn't revert back to using that. Glad I persevered but still miss the icons & tubes......