From what I gather reading the Tekton thread on avsforum, Tekton seems to be having problems keeping up with their orders and have seen massive delays in shipping dates and lots of broken promises. As for Zu, I like the idea of using high sensitivity coaxial drivers, but
these measurements are terrifying. JTR is doing the same concept
here with their single 8, and I think they will measure a whole hell of a lot better than the Zu speakers. A high sensitivity speaker that has my attention is the
Pi Fours, they are a proven and widely imitated design with lots of good measurements to back them up.
Gedlee and
AudioKinesis also look like some interesting, high-sensitivity designs, I would love to hear some of those speakers. Anyway, Gedlee and Pi may not have the hype and fancy websites of Zu or Tekton, but they are backed by stacks of good measurements and a long-standing reputation for reliability.