>>368776037
Whatever works for you. If you are wanting to just see what you're doing as you're painting then Substance will probably be useful, it's painting is significantly better than in blender.

>>368776113
I can think of maybe 4 people who can use it professionally here, don't kid yourself. If you're going to use it just to visualise what you're doing in your UVs and nothing else, then yes I'd consider it a crutch. If you try to learn how to do more than that then that's fair game.