According to the secret statistics thing on my LG, it’s running at 60Hz. It’s mostly slow on the homepage scrolling through the box art. Maybe it’s just controller lag. I’m running an 8bitdo pro 2 over bluetooth.
As far as I can tell based on my playtime, the only game the Steam Deck can play is Vampire Survivors. It keeps showing my lots of other games in my library, but I’m pretty sure Vampire Survivors (AKA, the game where you run around and it plays for you according to my son) is all this thing was made for.