From the facts I've read on it, I sure am glad I didn't pre-order the expansion. As your average greek player, I see nothing in it that will change the way I play the game, or make it more fun. More myth units? as zeus I already made all I wanted. Changed UU to respective buildings? Big whoop, with weapons of titans they already trained in no time, and certainly fast enough to drain your bank enough to nothing.
New tech? available in mythic, so pretty uninteresting.
I suppose the nerfs to norse amount to a beefs to greek, but honestly eggy was more of a pain lately, and I only see ancestors getting more powerful.
All in all, there were alot of balance changes, but nothing I wouldn't have expected to see in a patch. As I'm not interested in playing a new civ that is merely a hybrid of two others, AND a post mythic chenge to the game which will never be a factor in competative play-I'll be in the old rooms. Maybe room enough for me to move up the ranks in ratings now =)