Right now would be the best time to hit exo/lim. A lot of the limited players aren't even playing, and most of the top exo is trash.
Lol, theres like 500xp between Exo and high limited. Hardly doubt now is better than a rank reset to hit limited..
Really though, it's an over-time affair. You must generally win and not lose... then do it again the next day. And the next day.