I own a Steam controller and use it for my living room projector setup.
I have not played MWO with it yet because i'm a too competitive nature to abandon good old KBM, but for controlling Windows (Steams big picture mode can be disabled/minimized) and playing turn-based KBM games like Battletech it's better than most couch-compatible alternatives.
The trackpad that emulates the mouse is precise enough to hit even tiny stuff relatively quickly with some practice (at least on a big projector screen). When playing a shooter-type game you will probably have some overshoot and precision problems compared to a real mouse, so it's not my first choice for MWO. But i think it should work way better than a regular gamepad or most cheap joysticks.
It even got a clever text-input method that's fast enough to use it for occasional text-input like google searches with some training, but it can't replace a real keyboard of cause. I would not write longer texts with it.
So in verdict i don't regret buying it, for slower-paced applications it works very well. It just needs some getting used to.
Since you already bought one, just try it out and take your time to practice using the trackpad (it may feel weird first). If you don't get the hang of it after a few days you can still return it...
Edited by Daggett, 29 November 2018 - 08:44 AM.