Nathan has a review of the interesting N501 over on Headfonia. This is a hybrid headphone containing a dynamic and a e-stat (????) driver. While I have spent much time researching I can’t identify what an e-stat driver is. Since you don’t need an energizer to drive the headphone it isn’t an electrostatic. Who knows. Go read the article and see what Nathan thinks of the N501.
BTW, if you are interested in trying an electrostatic head over to Amazon or KOSS’ website and look at the KOSS ESP-950. This is an incredible electrostatic headphone with a lifetime warranty for $600-$800 depending on the time of year.