Been trying Control on the deck this eve.
Runs smooth as butter with settings at medium, 40hz, 40fps, 540p and using Steam OS FSR to upscale. I love the easy 40hz setting of Steam OS and I'm finding the system level FSR upscaling 540p to 720p very acceptable visual quality. Text takes the biggest hit in fidelity but apart from that I think it's really worth it for the extra performance. You can't hit 40fps for example at 720p unless you set everything to low.
Steam OS is really growing on me, and the Deck runs this game 'better' and at higher fps than my PS4 Pro. I know it's not the same "resolution", but on the small screen the PPI is high, so it is objectively better. Crazy really for a handheld device.