I'm replaying the Macedonia campaign after upgrading to Gold. While the objectives are the same so far, the way I'm accomplishing them is vastly improved. Diplomacy for example has really helped to make the game far less frustrating. With a little spare gold I can maintain a truce with a couple of factions to keep them off my back while I concentrate on the objectives and fighting off other factions. This has made the whole thing far less frustrating as I'm not always losing cities in the north while fighting battles in the south (as an example).
The new rules on recruitment are also making the game more strategic for me. I feel as if I can progress a little faster, and if I'm really good about setting up supply and logitics correctly I can get fresh troops to the front quickly and replenish those veteran units that take losses.
Essentially, the campaign objectives are the same, but it plays much more smoothly and quickly with the changes, enough so that it's almost a whole new game. I haven't even tried eithe rof the two new scenarios or sandbox mode yet, I've been too engrossed in completing the PoM campaign which I was never able to do in the original game.