I've seen one in person finally. It wasn't hooked up yet. It was much smaller than I expected, works very smoothly. I can't believe how simple it is. Just a housing with a motor on top and a hole on the bottom with 4 holes on the sides. The motor turns a housing on the inside to switch the open ports.
Too simple.
As far as head loss, it appears it is the same as adding 2 90elbows to your plumbing. Perhaps just one 90 on some ports depnding on how you plumb.
Very cool to see the thing on, it appears to be a very good alternative to acctuated ball valves, no way to program it really, but still, it appears solid and simple, and quiet.
Mike