I don' t own a handheld gaming device, but in my opinion, it's not really worth it. All the games I play are very lightweight, and most games I play on the move while I'm on a train or in the car are just mobile games. I'd honestly buy a laptop, a cheap one with a decent IGPU, so that I may be able to play CDDA or any of the 2D roguelikes I like to play. But then again, It's just my opinion. I can understand the appeal behind the steamdeck, not really the nintendo switch since I'm not a nintendo fan or really in love with their games since they're a pretty s*** company when it comes to anything else but their games. To answer your questions, If i did have a steamdeck, I wouldn't use it often since I already have a better alternative at home, and I wouldn't use it over my PC or laptop.