Green Mountain Callisto vs. Spendors ?

Hello. Has anybody heard the GMA Callistos and the Spendor 1/3 and/or the Spendor SP100?
I heard the Spendor line and the Green Mountain Callistos at the Rocky Mountain Audio Fest. The Spendors were impressive, good sound and imaging. Down the hall were the Callistos and they just made more music, captivated me like no other in a monitor type speaker. I bought the Callistos and I am still impressed by them.