"The model I got was the 2.5ghz 4gb radeon model, the reason being I wanted the better graphics card in order to play a few games. I think the discrete graphics is a big part of the extra price on the 2.5ghz model. I'd be fairly confident that the 2.3ghz 2gb intel model would play 1080p smoothly through plex. The integrated graphics should be capable of accelerating the decoding, and the i5 is a fairly powerful chip. If you're just using plex 2gb ram should be fine, but if you're using it as a desktop too I'd get at least 4gb. Keep in mind RAM is much cheaper from a third party and is trivial to install on the new minis." - acous