Regarding FSR - It is useful for some games, but not for all. This isn't a magical silver bullet that will net you extra FPS in all games - your results will vary between them (anything from not working at all, to losing FPS, to working very well and gaining FPS).

If your processor is the bottleneck, no amount of rendering at lower resolutions will help your framerate, so be sure that your graphics card is getting maxed out before expecting extra frames from using Lossless Scaling's implementation of FSR.

As an example of how well it works when it - you know - works, I normally get about 170fps at a certain part of Divinity: Original Sin 2 when rendering at 1080p. Rendering at 720p and upscaling using FSR, I get around 240fps in the very same location. The image quality isn't as good as native 1080p, but it's a damn sight better than 720p and those extra frames could mean the difference between 45fps and 60fps if you're running on a weak card.

For some games, this will likely be an invaluable tool for running at smoother framerates on the Steam Deck or on an existing portable device (AYA Neo, GPD Win 3 / Max etc.)

Recommended, but temper your expectations a little before purchasing.