Oh cool, I'm in pretty much the exact same boat with PDN!
You can definitely make maps on par with those made in Photoshop/GIMP with it. Occasionally, there will be something you can't find a way to exactly replicate, but usually there's either a plugin you can download to give you whatever you need or you can make up a workaround without too much extra work.
Maybe I ought to do a PDN tutorial of my style... (not that it's all that unique, except in the specifics of making things.)