For steam deck what the best client/in game resolution settings?

Whats better to do? I have the mbps set to 150mbps. For some reason I notice some games look better at the native resolution of the steam deck (1280x800) then running at higher resolution like 1920x1200 and some don't look good at the native resolution and need to be set to a higher resolution to look like native.

So im trying to figure out whats better to do? i wish i had 2 steam deck so i could compare.

Client 1280x800, in game 1280x800 150mbps

Client 1280x800, in game 1920x1200? 150mbps

OR

Client 1920x1200, in game 1920x1200? 150mbps.