Months later I still haven't managed to get through a ClearPass eval.
Between the cost of the product on the state price lists, my less than fond view of the UI, and the complexity of figuring out how to port our existing FreeRADIUS/PostgreSQL/Samba based policy over to ClearPass's UI my eval of the product keeps finding it's way on the bottom of my very long TODO list.
Since Apple shipped Bluetooth LE based discovery my interest in AirGroup has frankly evaporated. We hardwire the Apple TVs with static IPs, tell the implementers to set the rotating on-screen passcode option, and poke the firewall holes needed for iPads on wireless to get to them. It's work as well as an Apple TV can be expected to work with no need to over engineer it with proprietary mDNS proxying schemes.
Apple wireless device discovery of wired printers can be accomplished through static DNS entries via DNS-SD and DHCP settings.
The last piece I'm waiting for is Google to ship the Chromecast update they demoed during Google I/O in June. If they implement the geolocation based discovery via Google Cloud Services as I'd expect then we have a screencasting solution for Android. At that point we'd have all of our bases covered. The only wrenches in this are if Android screenshare somehow doesn't work the same way Chromecast enabled apps work and the fact the Chromecast is 2.4GHz only. Hoping the first won't be a problem and praying they do a hardware rev that adds 5 GHz soon.
At the end of the day I can't justify the financial cost and time cost that deploying AirGroup would be to implement. This also hurts the cost/benefit of ClearPass in view of us having something that already works.
I am still considering deploying a small ClearPass install just for guest functionality but screenshots I see of it are not flattering when compared to PacketFence's screenshots. They need some serious web and graphic designer love for the out of the box experierence.