Another limitation is that can handle 1,024 clients to 128 APs and 2,048 clients per Unleashed network in bridge mode (gateway mode supports up to 25 APs and 512 clients).
Gives you more flexibility along with administration from anywhere and access to Ruckus Analytics (this is a tool that gives you more information about network traffic).It is scalable in terms of the number of APs and Switches it also offers redundancy on the network side.
Adding to the wealth of information provided by Fernando, I'd comment:
1. Yes, all Wi-Fi 5 (Wave 2) and Wi-Fi 6 models can work together in Unleashed. Your R510 and T310 are the former. An Unleashed deployment supports a single version of firmware, so providing the Ruckus APs all support that version, you are good to go.
2. Cloud is a subscription-based platform. Cloud make supporting deployments across multiple sites very easy as the APs automatically connect and are provisioned. Also Cloud is virtually unlimited in terms of AP and switch management capacity. Cloud also has more features for customising the network than Unleashed, as well as enhanced guest-access options. All Ruckus APs will be supported in Cloud whereas some very high-performance APs may not be supported by Unleashed. e.g. R760.
The Unleashed master operates as a 'standard' AP as well as being the Master. There is the option to disable AP radio functions if you have specifically elected Master and Standby APs but this is optional. E.g. the APs are located in a network cabinet rather than deployed in rooms/corridors/etc.