The 24dbi dish antenna was part of the existing installation before I arrived. It basically serves to put a wireless signal down onto a lower part of campus. It has done an ok job, the width is a little narrow, as you mentioned, but distance is a bigger issue as our campus isn't very wide but longer. I've looked into an Omni directional antenna solution but cant afford to loose distance. The longest distance traveled is about 500 yards (figuring high).
I have looked at adding an amplifier to help with a stronger signal. Our biggest issue right now is our Linksys WRT54G. It locks up a few times a week and seems to be an issue with Linksys firmware a well as user limits so we'd like a simple unit that can handle greater than 30 consecutive users, as that seems to be the issue with the Linksys.