The ZD back is a very good back at low speeds and can produce stunning results, better than any 35mm Kamera in terms if image "feeling" due to the different lens focals and makes. It also has the possibility to make stunning IR photography by simply exchanging the filter in front of the sensor.
I am selling a complete kit, ZDback, AFD2 body, 80mm, 150mm 2,8 manual focus and the 375 euro worth IR photography filter. Only 3475 euro for the complete set.