Photoshop is best as a suite program, but if you're looking for individual tasks you're trying to accomplish, there are many programs that do specific task better.
If you're looking for a realistic painting program, ArtRage will destroy photoshop because of tablet capabilities, paint like effects, better palet for painting.
If you're looking for photo editing, Corel does a better job on filters.
If you're looking for sketching, i gotta say hands down autodesk sketchbook has it beat.
Photoshop needs to get better on tablets, i have an intuos4 and i get lots of lag from pressing my pen on the surface to the reaction, if you have a monitor its the same issue, i've seen it on multiple computers like that. That would be my only complaint.