I only did 1.1 and 1.2 of the device prep because I've gone for standalone OpenELEC.
You may see a few posts near the end of that thread from me. The fan can get a little noisy but I think that's because I'm doing some HQ Deinterlacing and scaling which is quite CPU heavy. For standard 1080p playback it should be quiet/silent, all done by the Intel HD graphics with ease.
Remember you'll need a remote, phone app or some sort of thing to control it (keyboard+mouse bleurgh)