I understand the 'wow' factor that UI2 + Overlay has. But it also has, in a significant number of cases, the opposite reaction from family members. We used to use UI2 + Overlay as our standard config on MD's and we stopped doing that because for many people it looked dated and was a challenge to use with a gyration style remote too. It's one of those features that looks great in a demo when someone see's it used briefly as it delivers a lot of eye-candy - but in real use its actually not that friendly to navigate or use (we have plenty of user feedback on that!).
Secondly it proved to be the single most frustrating setup area for both installers & for software customers. getting reliable installs on MD's using UI2 + overlay was always a challenge and very often tripped people up. Using a SmartTV, a Rpi based media player or a commercial media player presents a much less challenging UI as it aligns more closely with how other devices work, and for most people seems more familiar to them in use. I'm certainly not holding up SmartTV's or even Raspbmc as having the best UI in the world, but in general they seem to be easier for most casual users to handle.
One last thing, obviously running a full MD/Orbiter on a Rpi is now possible. But you still have all the complexity of the MD/Orbiter code base to deal with and fighting X etc when configuring the MD. Our experience of that with large numbers of systems, and even larger overall numbers of MD's, is that you can expect a high failure rate of those MD's from software issues. Combine that with major energy savings and you have a big reason to not use MD's (obviously if your using Rpi hardware energy use is not a factor either way of course).
All the best
Andy
