My opinion only. I have snapseed on my iPad but not on the Mac. I wouldn't use it for raw processing. I think it will be great for jpegs or tiffs, though. Kinda feel the same about pixelmator. It depends on what you're wanting to do in post processing. If you give us a picture of what kinds of things you're wanting to do in post and what kind of files you're working on then we can give you some good pointers.