I've remembered my old ML CLS IIz fondly. They are amazing in what they do right. Fast, transparent and great with Amta-sphere (and other) OTL's. These aren't for everyone, but I really liked them.
I totally agree w/ Rloggie, (except I still have mine ;-) You can't really go wrong with the earlier CLS models either and tube amps (see my system) are definitely the way to go since you're only driving a stat panel. Now that the transient response of some modern subwoofers (such as the self-powered MartinLogan Depth or Descent) can match that of an electrostatic panel, adding seamless bass is easy.
Also, ML still supplies the electrostatic elements for these speakers for ~ $900/pair + shipping. I know of a nice pair of CLS-I's I spied on CL in S.F. that are still available I believe.