Just tested my Surface Pro 3 with the SP4 Docking... My Displays ( 2 x DELL U2415, daisy chain) still dont work with the docking... Not even only one display works with the docking.
I use the Surface Pro 3 with the new Docking. Everything works nice until the Surface goes to sleep. If I wake up the device I have problems to connect to the external monitor. This means, I have to unplug the docking or to reboot the device.
Mine has been working perfectly with my SP3 - connected to two 2560x1440 miniDP displays (Acer K272HUL, ecah connected to a miniDP port - dropped daisy chaining), ethernet, USB 3 HD, Logitech USB speakers, and an HP LaserJet 4000T