I'm in the same boat, well I was... We also found that the old six unit Ruckus system won't support the newer Ruckus APS even if we wanted to upgrade those for more powerful ones. I don't like companies who do that kinda thing. IMO its just a legal method of extortion, a business model followed by the likes of Micro$haft, Int3l etc. Ruckus seem to also have a licensing model similar to MS CALS where you pay a licence for each AP. That also stinks...
Decided to divide the school into two zones, one using the 6 Ruckus APs and controller, and the other uses 7 new Unifi AP-LR units. Working fine, with a small glitch in the zone where Wifi switches between the two systems, but it doesn't get in the way much since its in our atrium area. I love the Unifi software controller - very easy to use, and unlimited APs. The only downside has been that I can't use my exisiting PoE switches, since the Unifi APs use 24v PoE, not 12v. However Ubiquiti offers PoE 8port switches for little over €100, which ain't bad.
Now I'm at a crossroads - government (in my country) is offering 100% funding for upgrading network infrastructure. So I have a chance to go 100% either Ubiquiti or Ruckus. Decisions decisions...