Single player: the campaign is poor stuff and extremely disappointing after the excellent campaigns in AoK and The Conquerors. Skirmish is good - playing against "Hard" AI is excellent preparation for going on line, as well as being fun in its own right.
Multi-player: a step up, because human players don't behave as predictably as the AI does. Brilliant fun, but so intense that I can't take more than a couple of games per day.
If you liked AoK and The Conquerors, you'll like this, with the added dimension given by the Home City concept. Recommended.