Daimbert - I have compared Devores with GMAs and to my ears the GMAs are a much more satisfying speaker if you're looking for transparency to the source, pinpoint imaging, 3-D sound stage, neutral response, dynamics and non-fatiguing sound. It's tough to match the results of the GMA's phase-coherent drivers and extremely high-quality crossovers, I think. The Devores, though, are probably just about as good in their own way when it comes to "musicality" and conveying emotion - they've got more of a "high-efficiency" sound to my ears, and they do have the advantage of being more efficient if you're dealing with very low-powered amps.
That said, you do have a pretty big room, so if you went with the Europas, pairing them with a sub would probably be a must. I think the recs for Vandys and Merlins also make sense, based on your room size.