SteamOS is a controller-first environment, which will give you that console feel. It's just so well done.
I can't speak to performance but I've heard game streaming works really well on the Deck.
I play a lot of "couch co-op" games with my kids while docked to a TV. Low requirements and very console-oriented. Compared to the Switch, here are some things that I bump into:
1. If you have 4 identical controllers, figuring out which is "1", "2", etc is hard. The Switch uses colors and LEDs to make this easy.
2. You need to walk over to wake it up. A controller can't wake it up if it's sleeping.
3. If you pair one of your identical controllers to something else, pairing it back is clunky since you don't know which one needs reconnecting.
But on the positive side, my young kids aren't put off by the leaky abstraction over PC gaming. They actually kind of marvel at the wide range the little device has but admit the advanced wizardry (game mods, desktop mode) can only be wielded effectively by Dad.