If you're using an 18:9 phone, you'll notice that you'll have black boxes on either side of the game window. Side-by-side, I couldn't see any input lag or other noticeable signs of latency between the two displays. But for every game I tested, I started off by sitting at my desk with my Pixel 2 XL on a phone stand under my main monitor.

Latency overall was surprisingly minimal I tried playing in different areas of my apartment and didn't notice any difference. Since this isn't a review of the Steam Controller, let's move on. So if you're planning to play FPS games primarily, then I'd suggest something different like a Moga Pro or something similar. Granted, I don't play shooters with a controller, but no matter how I tweaked the settings, I had a hard time. I tested Destiny 2, Overwatch, and Doom (2016) and while playable, I was not too thrilled with how it handled them. If you're familiar with the Steam Controller, then you'll know it's not well-suited to first-person shooters as a matter of fact, it can be downright awful in some circumstances.

Google tv steam link