Hope I'm not too late but I have owned the Europa, Europa Max and the Callisto. My friend owns the EOS HD's and previously owned the Calypso. I am intimately familiar with Roy from Green Mountains work.
With that being said, I can honestly say that Green Mountains are one of the most satisfying line of speakers I have ever owned. However, as my desire to own a more full range loudspeaker developed, the Green Mountains became unobtainable for me. I would have had to either add a sub to my Callisto's or move on. I chose to move on. There are still times when I pine for the unrivaled clarity that Green Mountains offer but my Magnepan 1.7 fit the bill for me a little better. I still believe though that there is not a loudspeaker line that offers more musical resolution and coherence within their specified frequency ranges.
Green Mountains are by far one of the most transparent and clear loudspeakers out there. They do well with medium power tube amps and solid state alike. They are not perfect but they are closer to perfect than anything else I've heard. Sure, there are warmer speakers, more full range, slightly more top end extension BUT nothing, in my opinion does most things as well as them. Vandersteen's come real close but the Greens edge them out slightly when I comes to overall clarity and transparency.
Be careful though, most other speakers sound phasey once u experience the Green Mountains. Also, Green Mountains are awfully expensive when full range is desired.
Lastly, the look is either love or hate. I was leaning more toward the hate camp.
Best of luck and buying them is never a mistake!
