I've had the Calisto for about 2 years now. Bought it 2nd hand for A$3000. It is a high sensitivity speaker suited to Valve amps. I run it on a modified NVA AP35 with a separate powersupply. The front end at the moment is a Marantz 63IIKI, Mircromega Duo DAC and a audio alchemy digital transmission interface. The sound is fast, dynamic and extremely detailed. Bass is tight, fast but does not go very low. The imaging is amazing on these speakers. The only drawback is it can sound slighly harsh on poor recordings. It will sound alot better with a pair of valve amps such as the silver nights or one of audio note's single ended designs. 4 stars with transistor amps, 5 stars with valve amps.