Hail and hello!
I'm a veteran MMO player (see list at bottom of post) who's just now discovered Istaria. I remember hearing about it as Horizons ages ago, but never checked into it for some reason.
I read a series of journal-like posts by a guy called Rihahn on MMORPG.com's Istaria forums. That's what really caught my attention. I'm now playing and having a blast, and my wife is going to be joining in too as soon as her new computer arrives in the mail.
Right at the moment, I don't know What's Best or Most Fun, so I'm thinking of going Spearman/Weaponsmith.