I would love if sets were level 70 gear, starting to drop in circa Act 2 Nightmare at a tangible rates.
Right now green items are signet fodder 95% of the time. Sometimes you find a good base item such as Witchhunter's Hood which is great for replacing your TU or RW. But these are few and far between. Most set items have disproportionately high requirements (strength, rarity) for their affixes. And getting a full set playing ssf isn't very feasible. By that time you will have some SU's, perhaps a great rune too. And crapload of shrines to come up with something better than sets.