Below are the information I tried to put in based on your query. I hope this answers your query:
Unleashed RUCKUS Unleashed APs are designed for small and midsize businesses with a single location or multiple locations with up to 128 APs, 2048 clients and 8 switches per deployment. Unleashed integrates the controller and access point features installed on a access point (So called Controller-less. No extra hardware controller required, no per AP license required), a enterprise wifi solution from Ruckus for small business. The concept is similar to IAP (Instant Access Point) from Aruba, Mobility Express from Cisco.
Even tough the Unleashed included many ZoneDirector features, Unleashed does not provide the entire ZoneDirector feature set. Some of the Zone Director features are either not supported, supported but with limitations, or are currently unsupported but planned for a future release.
Standalone: Standalone or Solo firmwares makes the AP to run independent and and its configurations are local to taht AP only. If you are having more than 1 AP and running on standalone firmware, both the APs will be working independently and you need to manage\configure by logging into it individually.
Running a few in standalone your basically setting everything manually which can be fine depending on your needs. The main advantage you loose is centralized control, and more automated stuff a controller offers like channel coordination, load balancing, managing all the APs, centralised configuration, roaming etc.
Hi @CCX Having the APs in the controller\centralized managed version is more reliable and easy to manage when dealing with multiple. Even with Single AP you can use Unleashed version which will have more functions when in Standalone AP.