Hi,
Apologies for the strange post but could not think of a better place to ask. I have played with Rasplex for a while and have great admiration for the achievement on getting the Plex to run on such limited hardware.
I have acquired a midnight Gbox (2 A9 cores ARM, 1Gb RAM, Mali400 GPU) on which I wanted to experiment, mostly running plex from Android, but that turned out to be very disappointing. The only good option is XBMC on a openelec build, but I cannot bear to part from Plex.
You wouldn't necessarily have to abandon Plex, since there is a good Plex client add-on for XBMC, known as "PlexBMC".
I have installed this as an alternate plex client on each of my Android devices, though I normally use the 'real' "Plex for Android" clients on them. (The new Kepler client on units with ICS, and the older client on a phone with GingerBread Android.)
The only real drawback of using XBMC is that the main menu implementation really sucks when it comes to touch-screen or mouse control (any pointer interface), as it still is very much dependent on keyboard driven navigation. It can be used by touch-screen or mouse too, but it's really awkward (even with practice I only manage to hit the right menu command in appx 50% of my attempts using touch-screen). But fortunately that problem is unique to the main menu. As soon as you enter a media section everything's fine. And if you use a keyboard or remote DPad to navigate there is no problem at all even with the main menu.
In addition to XBMC itself you then need to install the following add-ons to it:
PlexBMC
PlexBMC script helper
Some PlexBMC-adapted XBMC skin, such as Amber or QuartzV3
Next you should open the configuration menu for the PlexBMC add-on and configure its method of contacting the PMS server, for which I always use a myPlex login, disabling the GDM option.
Once you have this stuff configured you can activate one of those skins and use its special command "Go Plex", which effectively transforms the XMBC GUI into a dedicated Plex client.
There are many more things you can configure of course, but the above are the basics you need in order to get started with PlexBMC.
Btw:
Naturally this stuff will work on just about any XBMC setup, not just for Android versions like I mentioned above.
I also have identical PlexBMC setups installed on several of my PCs.
Best regards: dlanor