Indeed it is hard. It's much easier if you have a friend or two with which to quest. Also the new level 75 minions help doing Azteca solo more tolerable.
To most yes Azteca is incredibly hard. If you have good gear a semi good pet and some good strategy you should do find but again it is a challenging world so prepare yourself
I have just completed Avalon and I am wondering if azteca is hard
Well I don't think so. It just depends how you look at it.
If you are having trouble with a boss and can't solo it, what do you do? Complain that the boss is impossible on the message boards, or get a friend to help?
Azteca is noticeably harder than Avalon, especially in Twin Giants. I personally don't think Azteca was too hard, because I soloed mobs and some bosses. Some things I would not think twice about soloing like Belloq and dungeons...
It is also about strategy. For the higher health mobs I have to have two feints on each enemy for me to kill, for the higher health bosses I have to have all my blades and all my traps in order to just barely kill the boss. I guess you could say it is "hard" but it is do-able.