As an RPG fan more than a RTS fan, this was the best game in the series.
However, Blizzard is about the one force in the galaxy that can get me to play another, just because they make such good stuff. Even if I can't stand the thought of playing an RTS, I'd go back to just to catch up on plot.
So, from this perspective, I say this game rocked. I loved it because it was so different. I think a lot of people hated the game for the same reasons I like it. It is smaller scale. It feels very squad like at time. You get a great sense of roleplaying. It doesn't feel too epic and overwhelming all the time.
I just really liked the smaller scale RPG feel to it. Hardcore real time strategy gamers are free to disagree, but from this roleplaying gamer, this was a great game.