Here is my opinion having used a bit of Pain Shop Pro and quite alot of Photoshop. Using photoshop you have this HUGE plus point that unlike Paint Shop Pro. in Photoshop you have thousands of thousands of tutorials that will cover each and every aspect of photoshop you would ever need for photo-editting. Apart from that I think that more then 80% of the digital photo-editting persons use Photoshop that opens another door for the photoshop users. You can ask your questions and you would get your answers immidiately (for example on this forum).
I'm not saying that Paint shop pro is a useless application. I'm just saying that unless you like to read thick books to learn a program or like to spend your time searching the internet for hours finding the answer to your simple questions you could go for Paint shop pro.


