Early action, yes, I do think you have to be pretty damn stellar, cause they are committing to you before seeing the majority of that year's apps. You pretty much have to be a the 75th percentiles of both LSAT and GPA from the previous year to have a shot. Usually you get deferred so they can review you later.
Early DECISION, on the other hand, is different. Here you might get away with having slightly (very slightly) lower numbers, cause you are TIED to that school. It might give you a bit of an edge at a school where you would be borderline. (If you have numbers at the 75th percentile, there's no reason to apply ED cause you'd probably get in regular decision anyways (and adcomms know this), and if your numbers suck then you'd probably get deferred anyways for later review.)
Whatever you decide to do, applying early (before Thanksgiving) is usually a very good idea.