Substance Painter/Designer Thread

So a friend recently bought them because they were on sale on Steam, it got me wondering about them. Do people on this forum use them often?, do people generally find them easy to learn to use?, I think next time there on sale I might consider them but not sure. Mainly curious what the benefits of them are since seems like a lot of people use them in AAA quality games. Basically I'm thinking it over because there quite expensive software's, I'm mainly working on my own projects by myself, concerned that there might be a steep learning curve. Love to hear what people think of them.