
Sometimes I tried to dive into 3DCoat but it happend everytime that I struggle with its UI and "how the things to be done". If you end up looking at buying 3DCoat let me know, currently selling much cheaper than here on the website. In the end I'm taking the Substance route for myself - I don't need the other capabilities offered by 3DCoat and don't typically hand paint my models, so I'm actually selling my 3DCoat license. tools that you wouldn't get with Substance. You get a lot of great modeling, sculpting, retopo, etc.

I know you mentioned you are only looking at the painting/UV features, but obviously 3DCoat is the better value proposition. 3DCoat has similar features, but it's going to be a destructive workflow, where Substance is much more non-destructive (maybe someone can share a better workflow for this in 3DCoat). You can apply a layer and then adjust it's mask through sliders for instance. It also does dynamic masking better than 3DCoat. Go search Gumroad or Artstation for "Substance" or "3DCoat" and you'll see what I mean. are much easier to find for Substance than for 3DCoat. For one, it's a much more popular tool, so tutorials, materials, brushes, masks, etc.

However, Substance has a lot of things going for it as well. 3DCoat also has vastly superior UV capabilities - I think currently Substance Painter is only doing Auto-unwrapping which works for some cases but isn't near as flexible as the tools you get from 3DCoat. You have a lot of control over your brushes and the smart materials are really good (though the default library is lacking). It works much more like Photoshop and isn't as confusing in my opinion to just apply some paint. I think for hand-painting your textures, 3DCoat is still the better tool.
