New to the Ruckus brand entirely and am curious what functionality (if any) will be lost using a controller less platform such as the R600 unleashed. Mainly I am concerned about roaming functionality over multiple APs and if that functionality is present in the unleashed line or if a controller (Zone Director?) must be present.
In addition, I am curious how the R600 stacks up against the newer Ubiquiti lineup (UAP-AC-PRO) before I finalize my purchase decision.
I'd personally recommend steering clear of the Ubiquiti lineup unless you have a very small density type deployment (for example, low-budget hotel where you have lots AP's to cover a wide space but only 1 or 2 people per room).
Everything that I've tried that uses Broadcom AC chipsets with chip-based beamforming seems to do great for 1 client per AP or a few clients per AP (sometimes even faster than midrange Ruckus), but quickly breaks down once you start adding even just 10 clients, or worse, introduce interference or start trying longer distances. They all look fantastic on paper though.
You should let Ruckus comment on their roadmap. My observation is that IPv6 bridging seems to have worked when I had my R600 set up for Unleashed. And it's also worth noting, your investment isn't really wasted -- the R600 Unleashed can be converted to Standalone or ZD-managed via firmware updates, though Ruckus officially doesn't really recommend that because any warranty-replaced units will ship as Unleashed. But if you are knowledgeable and managing a small-ish installation, you can probably deal with flashing replacement units back to whatever variant you wish.
But overall, I would say, there's virtually no contest between the R600 and Ubiquiti's lineup.