I own both 3d coat and Substance Painter and while painter has some really cool features like edge wear effects, painting with particles etc you'll still need Substance Designer and a good map baking solution to get the most out of it. Also performance wise 3d coat is vastly more responsive than Substance Painter, and that holds true even if painting 8k or 16k maps. Painter lags quite badly even at it's lesser 4k limit.
The Substance toolset definitely excels in creating textures for games and I'm a fan of all their software, but outside of games it pales in comparison to the likes of 3d coat, Mudbox and Mari. For high fidelity texture painting and a more artist friendly 'painterly feel' I'd definitely recommend 3d coat at this point. The deal sealer being PBR now getting implemented in 3d coat, which was previously it's only weakness in this comparison.