AMD FSR 1.0 vs. FSR 2.0: Which upscaling tech should you use?

We want our cake, and you bet we're eating it too! What gamer doesn't want beautiful graphics and high frame rates? AMD's FSR, or FidelityFX Super Resolution, does just that by using upscaling technology. To compete with Nvidia's DLSS (or Deep Learning Super Sampling) in the battle for the best graphics cards, AMD has introduced FSR 2.0--but the original FSR is sticking around and still widely available. Should you be using FSR 1.0 or FSR 2.0?