The August Celestials felt like the slowest reputation grind. There's no storyline that coincides with it like every other reputation. You just get sent to one of four available quest hubs for 4 or 5 quests daily (depending on the hub). It took me... It took me a really long time to get this done the old way, during 5.0. The only reason the grind is long is because of the minuscule amount of quests that you can get daily.
Like the Shado-Pan, you don't have access to the August Celestials reputation without being revered with the Golden Lotus (except in LFD; your bonus reputation can be the August Celestials or the Shado-Pan right off the bat). This also includes for the work orders that came in 5.2.
Honestly, there's not a lot to be said about the August Celestials in general. They're the gods, they're pretty cool, you do a few different little lines that involve beating champions, protecting Nizuao, and beating the crap out of Sha. Exalted isn't even climactic - and the mount isn't either. Basically, the August Celestials are a nice, simple little faction that takes forever to do.
Now, the time is significantly shortened because of the 1000 extra rep (pre-commendation) you can per day due to dungeon/scenario/work orders. Let me tell you, those are the best thing to come out of 5.2. I'm able to get more reputations done so I can get my patterns and stuff on my alts. It's a wonderful thing.
There are only a few achievements associated with the August Celestials:
Yak Attack: This is really hard, and I haven't been able to do it yet. Those Klaxxi mobs hurt, man! Anyway, you have to wipe out 15 of the attackers there, and the only real way to do that is to drag a bunch of them in front of Niuzao on a day that he's running around instead of sitting stationary.
Champion of Chi-Ji: The only "questline" that really feels like it happens here is with Chi-Ji, where, after you do the initial 3 quests, you get a 4th quest that is a different "challenger" every day. Eventually (after 15 different challengers), you'll get this achievement.
Finish Them! There are 11 (technically 8, because one is a team of three and the other a team of two) different challengers to fight during the Temple of the White Tiger dailies. Beat them all, get achievement. Easy enough, right?
That's basically it. The August Celestials are a straight-forward, simple little grind that takes forever and ever and has no grand finale like the other Pandaria factions.
Oh, you get this pretty mount, if you want, for 7k gold. It looks just like the Golden Cloud Serpent, but with cool looking lightning graphics.
Did you finish your August Celestials rep? How did that go for you? Share some thoughts in the comments, have a great day, and we'll see you back here again!