Guffer, what are you going to be using on the RPi's? I trialled one in the bedroom with XBMC on but in the end got fed up of the lack of codec support (I have some stuff that is native MPEG2 so while the RPi supports VC-1 etc with additional codec licenses there was still a significant amount of stuff it b0rked at) and bugs (no HD streaming from the TVHeadend box, for example) and replaced it with a near silent mini PC the same as I have downstairs.. but I'd still like to use the RPi's somewhere for music rather than video (say in the garage, bathroom & kitchen)..
XMBC too, I know about the codec limitations but there are packs you can get which help. I have been preparing my media collection in to the compatible formats for the last year anyway 
I was running XBMC on my Pi, also tried Plex on it, both work but very clunky & slow.
I recently bought a NowTV box for £9.99
https://shop.nowtv.com/It's basically a Roku box, but WiFi only and a restricted apps (easily got around) for £9.99 including HDMI cable it's a bargin. Sky must be selling these at a loss, so can't see them doing these long term.
I put mine in developer mode and installed Plex on it, now links to my PC for all my Media needs. Works very well, much faster than Pi. Also NowTV box has BBC iPlayer, C5 on Demand, Sky News, Radio, Spotify ect.
NowTV for Movies works quite well too, good stream quality and works well.
Planning on getting another, as this one will go hopefully in my new front room with big tv in a "minimal" tech setup of just TV and that box.