Officially off stock firmware on all three Android devices at home.
The Toshiba Thrive is running a CyanogenMod 10 build (JellyBean) called Dastardly Dingo. The UI is a Go Launcher HD app.
Just as the warranty on the SII ran out, I rooted and upgraded the firmware to the latest JellyBean build. An AOKP JellyBean build.
The UI is a Nova Launcher, providing additional functionality to the stock launcher.
The final device, a Nexus one, is running Android 2.3.7 (Gingerbread), limited only by it's hardware specs from upgrading to ICS or JellyBean.
The biggest difference, of course, is the really powerful Google Now application, that syncs itself across both the JellyBean devices. More details post on Now at some point later, but safe to say, one of the first, well polished, functional and useful personal assistants on today's phones.
Whew - all aboard on JellyBean.