Ok, Chains of Promathia has been out for over a year now, and SE has released (almost) all of the content we're going to get from this storyline. (The exception being perhaps Bahamut as a final summons. Jury's still out on this one.)
I mean, we gained many new areas that have become very useful.
Bibiki Bay (excellent exp 60-70+), the Tavnazian Archepalageo (meadows is great exp, lots of funky fun quests, a nice lag-free spot to be your home once you have the outpost warp).
Ulliegurand Range, Attowha Chasm...
Lots of new NM/HNMs that drop some awesome stuff, and more ways to get some of the older stuff (Abjurations). The 3 wyrms are very exciting and generally kickass to look at.
Lots of ENMs that offer awesome rewards, experience points, and generally interesting battles. They level range is huge and can provide good rewards for all levels.
Then there's the missions. They can be so frustrating, but at the same time the most fun. I'm only personally on Riverne Site #B01 now, but so far it's been an awesome ride. I remember when the expansion came out and everyone jumped to start the Promyvions. These were so hellishly hard at first. People took entire alliances into the zones to deal with the difficulty of the 3rd & 4th floors. Back then you have a very small amount of time to jump on the teleporter after beating the memory recepticle. I'm really glad SE saw how bad this was when you're trying to fit 18 people on a very tiny circle. Then there was the NM at the end. Some of them weren't too bad (Dem, Mea), but others were crazy (holla). Sleep/Curse/Gravity AoEs are not fun. But with a ton of items, Animas (which took 1 RL day to get per anima back then) we prevailed and marched forth.
Then SE nerfed them a bit and a single party could make it to the Spire without much trouble and a lot of running on the 4th floor. ;)
Now we have a ton of people who have completed the whole storyline, have those freaking awesome rings and do Limbus with other folks, kill Jailers, and sit there, dead, cursing Absolute Virtue for being so freakin impossible.
All in all CoP has held me close to my monitor during all the awesome storyline elements, the great music, and kickass cutscenes and I'm only on ch. 4. I can't wait to get to the end.
So I ask my fellow adventurers, what do you think of this expansion? Do you think SE can keep up the good work (job updates aside PLEASE) with ToAU? I certainly hope so.