PS4/WiiU owner and SteamOS user here, and I can tell you, my (homemade) Steam Machine is looking a lot more activity than any of the other consoles mentioned..

You are right that indies are one of the strongest sellers for the platform, but you can’t really demerit games such as Assault Android Cactus, Towerfall or RONIN (for example), which actually are awesome to couch games (especially in case of local multiplayer for the first two).

About AAA games such as Dying Light and Shadow of Mordor, I can confirm they play a lot better on it than its console counterparts, AAA are coming slowly but steadily and better optimized.. And no issue with new releases not available for Linux, as I can easily use a previous Windows rig to stream them from my room..

Also, one of the greatest things of this machine is that I can use whathever controller I want, wired or wireless, tested with up to 4 controllers, effortlessly, most of the time getting even corresponding button bindings (PS4 controllers usually shows x, square, triangle and circle buttons accordingly for a lot of games).. And consider I don’t even have a Steam Controller yet, but I’m pretty satified with my build as you may have noticed..

And consider neither the platform nor the OS have been officially released yet! So this machines are definitely something to keep an eye on for the next couple of years, as I’m pretty sure they will present a lot of good surprises for anyone who consider himself/herself a gamer..