Is its 1080p performance perfect? It'd be an interesting option here, if so. The Pi isn't up to the job, which seems to leave something of a toss-up between this and an Apple TV, suitably jailbroken for Matroska support.
So far so good — I threw a 1080p file at it last night and it did fine. Admittedly, most of my content is in 720p, because that was about all the Apple TV I used to use could deal with.