Driving them with an Odyssey Stratos. I have the Zu Mother powercord on the Odyssey and Zu Ibis speaker cables to the Druids.
I did not get to listen to them prior to buying. I spoke many times with Zu and was assured that if I was not happy, they would even pay the freight back to them. They have a 60 day in home trial, so for @ $70 shipping for the pair, you can really get to know them.
This is one of the toughest things to decide on as it seems like a major leap of faith (being unheard), and also the commitment of receiving large packages VIA fedex and lugging them back if you are not happy.
There are a few other people that have purchased them, and others that tried and retuned them. Audiojerry has demoed them when they first came out, but returned them. I think that the reason was he could not get his sub to integrate with them (If this is incorrect Jerry, please correct me). The Druid 2 has much better Bass presence than the original version and the midrange is much smoother (not saying the original was not smooth, but there was room for improvement).
If you have any concerns, don't hesitate to call Zu, as they will honestly answer your questions. They have the best customer service that I have dealt with.