Totally, I have a desktop as my primary and a laptop for class, and I always have it charging next to my monitor on my desk, so it's not a problem. Additionally, some games I've played really benefit from a walkthrough (Tomb Raider Underworld, god damn puzzles were never clear and I always got stuck without a walkthrough), and I'd rather have it on a separate screen rather than having to pause and access my Steam Overlay to do it.
Main issue with using a phone/tablet is finding the optimal angle to prop it at when I am gaming on my desktop so I can look at it clearly. With a laptop screen this isn't a problem.
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