Electrostatics are hard to beat for vocals. That's one genre of music they really excel at.
I had the Druids, not the Essence. I now own Spires. By comparison the Druids sounded thick, slow and closed in. It was almost like listening to music in a tunnel. The Spires are open, very transparent and excel at acoustic and vocal music. The Spires can be a difficult load with impedance dropping down below 2Ohm so your amp needs to be up to the task.
I fully understand that these forums are for gathering information, but the last 4 threads from you have been about these speakers vs ??.
Just as Tricon Dave mentioned that they were slow and closed in sounding, dont let that influence you on your decision of trying these speakers....as this was in his system, in his room, and not yours. In your system and room , they might sound completely different, and might be just what you are wanting to hear from a speaker.
Buy a pair of the speakers and if you like them, then fine your search is over, and if not, sell them and move on.
You can compare 2 kinds of speakers all day long on this site and get answers all over the place...as there are way to many variables to deal with.
Have you researched to see if there is a dealer nearby that you can go and listen to the speakers ?
There is quite a differnce between the Essence and the Druids. I've owned and enjoyed them both, but found the Essence a more natural presentation with much improoved bass.
Tricon Dave, with your Druids did you adjust the height of the base to the spec's in the instructions? This had a definite impact with the sound of the bass and the response of the Druids.
I have owned Martin Logans and have heard the Zu speaker line regularly at my dealer, until recently, when they dropped the line. This is probably an overstated generalization, but I have found that all but the top Logans have limited output capabilities, and also they just don't seem to be voiced for rock music. Not that they couldn't do a good job with some rock. The Zu speakers on the other hand were born to play rock at high levels while still maintaining their core strengths. I feel that if rock and pop are the types of music you listen to most often then the Zu speakers are tough to beat, and extremely easy to drive.
I tend to agree somewhat with Riley, but may I suggest a slightly different approach. State the general area in which you reside, list the speakers you're interested in hearing, and ask if there are others in your general neck of the woods who would be willing to have you over for a listen. Then you arrive with a bottle of wine or six-pack for your host, few familiar cd's, and maybe even your amplifier or some other component. You then get to hear what you're interested in, and you get to meet another person in your area with a similar passion.
Good luck, Barry