ITE makes a dual band sector antenna, is well. kind of OK, the 5GHZ side is decent but the 2.4 ghz side is awful. the beam spread is shot very high into horizon as the 5ghz edge is down to distance. the concepts great and would really reduce our co-location costs of such an antenna was around. or if some sort of antenna kit that would allow the 2.4 and 5ghz antennas to appear as one and bolt up as one with a similar top lobe for down tilt... from our experience the tower companies don't care as much about the size (to a point) of our antennas, but get us for every antenna mounted. I haven't pushed the envelope with size much, but we didn't get charged any different for the old terra wave 15 db 900 mhz sectors we had years ago, they stood 6' tall and a 9" face.
the recommended dual slant for the 2.4 ghz EPMP is great, it would be nice to only get tabbed for 4 sectors rather than 8 when we put both 2.4 and 5 ghz up. we usually get charged an extra $200/month for the 8 sector setup. so for us, the antennas would save a pretty good chunk of change, even if they retailed for 500/sector.
a dual band EPMP AP would be a perfect pair with this guy too ;)