I've not used substance enough to have an informed opinion, but from what I've seen its not just the tech that makes substance interesting (its ultimately a 2d compositor and paint package), but its the library of texture nodes and workflow that make it good at what it does.
The feature set of cops have interesting pros and cons. It's built into houdini, supports vex and vops, can has the ability to move data between 3d and 2d, all great. It's also little old, slow, unstable compared to other compositors.
There's not a lot of substance specific tutorials around as it would take some effort to get it to parity, but there's some interesting developments. Maybe you can be the one to tie it all together!
Quantico is creating a lot of cops nodes that are emulations of interesting substance nodes.
https://www.sidefx.com/forum/topic/69233/ [
www.sidefx.com]
The gamedev/sidefx labs new maps bakers use cops under the hood to generate base maps and transfer high->low, like substance does, this presentation explains how its done:
https://www.youtube.com/watch?v=B8HqBuH9xew [
www.youtube.com]
Fabrico Chamon is very busy, he made a full substance style cops thing about a year ago, I'm sure it'll give you some ideas:
https://vimeo.com/288436861 [
vimeo.com]