the mezzos are 90-92 db (sorry i forgot which) efficient. i have a pair and absoultely love them. i bought them new a bit over a year ago for under $10k. i first powered them with a 45 wpc tube amp and shortly thereafter upgraded to 140 wpc tube mono's. they sounded good with the little amp but they absolutely sing with the mono's. i auditioned a number of speakers, including the eggy rosas and andreas. as between the andreas and the mezzos the decision was tough. i like the styling of both and the fact that the eggy's are made in the u.s. they were both quite analytical, but i would probably give the analytical edge to the eggys (the imaging and with of the soundstage was awesome). but, i was a bit concerned about the power required to run the eggy's (i knew that i was going to upgrade my power source, but was not sure when). more importantly (to me), the mezzo's mids are really fluid and incredibly realistic. the highs are crisp without sounding harsh or etchy and the bottom end, when powered well, is really tight. in short, i found them an overall more musical speaker--natural sounding, highly detailed, good imaging and soundstage and really, really fun to listen to. if you can find a deal they're well worth it. good luck.
