Level 15 dungeon gear seems better/comparable to some level 20 quest stuff, so that loosely fits the criteria. Depending on how you feel about melding materia into things you'll outlevel is another matter, too. I'd only really consider it while leveling if you plan on leveling multiple jobs and tucking them away. Establishing a good crafter/gathering set probably isn't a bad idea, either.
Since there's no NMs in the XI "must camp me to get to epic loot" sense, however, you're pretty much left hanging short of some FATEs with unique drops like Odin and Behemoth. As well, some have achievements, too. Generally, I'd say this is for the better. Let the "status" come with all the **** retentive endgamers and eventually whatever comes of PvP. I just want to log in and play knowing I'm making decent progress toward something, be it leveling or getting new gear. So far, so good, at least.
Violence good. **** bad. Yay America.