In summary, Photoshop CS4 is the perfect software for professional photographers as well as the serious amateur photographers. A lot of graphic designers and web designers are also keen on using this software. On the other hand, Photoshop CS4 extended is really ideal for film, video, and also multimedia professionals.
For normal photo editing, darkroom will do the job and easy.
For CS, u need to learn a lot more for layer and 3D. required higher end PC to run smooth.
A pro can do the job well. other depend on set up.
I have CS-ext but seldom use use too complicated for simply editing.