I agree with Torniks and FestiveLongJohns. I use them later in the game in team games to cap around the flanks and force off enemy units trying to do the same.
They are good for this role as later in the game you can usually afford the expensive cost (in team games), and the main battles are taking the majority of your opponents army. Meaning pulling an AT unit and an infantry unit to deal with it can be too much of a hassle for your opponents.
![Honor icon](/images/replay/honor_icon.png)