I'm a long time Magnepan owner...I bought my first pair, Tympani 1d's, in 1978. I currently own a pair of 1.6's that I use in my bedroom system, and a pair of 1.7's in my living room. I also have a CC3 center chanel speaker there along with a pair of MMG's for surround duty.
The sound that a properly set up Magnepan system offers is really special for any music lover. What they do reproducing the human voice is their strongest asset. I've never heard another speaker reproduce a well recorded vocalist as well as Magnepans do.
I've owned many pairs over the years, including a pair of MG IIIa's with the true ribbon tweeter. They all gave me years of musical enjoyment. As others have mentioned, to sound their best they do need a good quality high current power amp, but there are many of those available today to choose from.
I've had many power amps over the years including a Phase Linear 400, GAS Ampzilla, Citation, Audio Research, plus a variety of the Nelson Pass era Threshold amps. I still have an Adcom GFA 555 II that is surplus at the moment, plus 4 of the classic Threshold offerings including a pure class A SA/4e. In the last year and a half I have discovered the Emotiva line of power amps which I am very impressed with. I have an XPA-2, a pair of XPA-1 mono blocks and an XPA-5...all of them work very well with Magnepan speakers.