I do a lot of flying and travel for work and the Steam Deck has been fantastic for it. My gaming laptop can't draw sufficient wattage from the airplane's power outlets so I couldn't use it for gaming in flight, so I needed another solution that wasn't gaming on my phone (let's face it, most mobile games suck).

The Steam Deck gives me that extra versatility when traveling. I find myself playing games that I wouldn't otherwise normally play due to the control scheme. I'm mainly a keyboard and mouse user so adapting to a controller for most things was a bit of a learning curve, but it's much easier when playing games well suited for it (Ace Combat 7, American Truck Simulator, Euro Truck Simulator 2, FEZ). My favorite though so far has been Grim Fandango Remastered. The controls are so intuitive that it's like the game was custom made for the Deck (despite the original being two decades old).

I haven't really played FPS even though there's a gyroscopic control scheme available, I miss the precision that the mouse enables. Hack and slash in TES 4 Oblivion works well though, but not really with bow and arrow shooting.

I also couldn't really do RTS for the same reason, even with the track pad like functionality.

It's great though for side scrollers, isometric RPGs, third person action adventure games, driving games, and simulators.