Angle is pretty much solely dependent upon gain. So a typical horn is about as good as the best patch array or a smaller parabolic reflector. But they are worse than both in the mechanical sense.
The higher the frequency the more practical horns become. From: Stefan Englhardt via Af Sent: Wednesday, October 15, 2014 1:51 AM To: af@afmug.com Subject: [AFMUG] Rflelements announcement This is realy something I did not expect: They announce Systems with Horn antennas. A quite different approach. Their sectors are directional antennas so coverage is not as good as with traditional antennas (Their marketing argues the opposite). But horn antennas should have very low sidelobes, a good FB-Ratio and allow small angles. So it should be possible to make a more dense deployment. What make me scare is the big opening where water and ice may cause damage.