From a gardener’s perspective, at least, “sweetness” is not the best metric to judge quality by. Yellow tomatoes are much less acidic and blander than red ones, which (IMHO) is not a desirable characteristic. Classic red tomatoes have an acidic bite that makes them “tomato-y” in a way that just sweetness does not. Grocery store tomatoes and picked green for shippability and never really develop any flavor at all.
Of course, YMMV.
