I have the Zu Tone monitors, and if they are anything like the Druids, this is what you will get IMO:
Good Stuff
1) A speaker with electrostatic speed and detail without the power requirements, limited sweet spot, and space requirements.
2) A speaker with absolutely huge soundstage, both front to back and side to side.
3) A speaker that is SET amp friendly, although I dispute Zu's claims about 101db sensitivity; see below.
Not So Good Stuff
1) Tonally, the speaker is very innaccurate. I spoke to Zu about this, and they claim that the speaker was tested for a very even frequency response in an anechoic chamber, but even after many hours of break-in, I dispute this. I have taken many measurements with varying measurement devices and techniques, and maintain my opinion that these speakers (at least my pair) are not accurate. If you read the article in the Jaunuary 2006 Absolute Sound about the 2nd Rethm speaker (which is full range), this IMO also describes the attributes of the Zu Tone (both positive and negative) almost perfectly (with the exception of high frequency extension, which Zu speakers have due to their supertweeter). The most apparent tonal anomalies of the Zu Tone's are a very peaky upper midrange (about 7-8 db, centered about 1.4kHz but going all the way to over 5kHz), and a reduced bass response (about 8 db) centered about 70hz.
2) As others have indicated, there seems to be a pretty long burn-in time (which reduces some hardness), but it is not nearly as dramatic as some have suggested.
3) Since they are so detailed, they are not forgiving of other sources in the chain, especially poorly recorded music, which there is an awful lot of.
I use digital EQ to correct the tonal anomalies described above. Once this is done, the 'sensitivity' of the speaker will be reduced. One reason I believe it measures so high is due to the big bump in the upper midrange (which requires less power than lower frequences), and the reduced bass output.
If you are willing to correct for these anomolies using EQ (or of course if you like the sound of the speakers without it), these speakers sound absolutely lovely. I've never heard a dynamic speaker sound so detailed and image so well, and I've had some pretty good speakers (including large Martin-Logan electrostatics). Even the bass once corrected, is very fast and detailed (although I am supplementing the low bass with a pair of subwoofers).
Good luck!