Hi Charles1dad, I still have the Mini Utopias. They're among that group of speakers that can be satisfying with tubes but, at times, can challenge an amplifier. My next speakers will have close to a ruler flat impedance - preferably above 8 ohms, but certainly over six. My problem has been that many of the high efficiency speakers that I find intriguing use somewhat radical solutions, and are difficult to audition. I really dislike committing to anything that I havent heard in my system.