Hi Jack, well one good reason is I don't use any Adobe software . I've been trying for several years now to build and build my PP knowledge using purely Capture NX2. I find it very very good and still lots I can do to extend myself and the quality of my images. Actually as an aside, the Nik website has a wealth of video and other teaching material that is extremely advanced. Plus I have always used Jason Odell's ebooks to provide my base knowledge.
But in particular I would live to have the "add canvas" function available via Photoshop, which as a Birder would be an invaluable feature, and I need to research ways and means of adding a signature and frames, both of which certainly add a sense of professionalism!