I don't have a lot of of super current AAA titles, so most of my games that didn't already work on Linux(most of what I buy) already worked on Wine. But with the Proton integration, I do appreciate that I don't have to run a separate Wine instance of steam and instead running my Windows games is far more transparent. I guess the only minor downside is that since the whole process is so transparent it makes it a bit more jarring when I do come across a game that doesn't work.