I can adjust the height by what speed I run my VS pump, and how far I open the valve. The valve will only control so much since it is essentially an on/off valve, so the most control comes from the pump speed. I have deck jets, scuppers and waterfalls all running off of this pump, so there is a bit of a balancing act when I have all features on.
I can shoot them completely over the pool if I get the pump speed high enough. In fact, when I turn them on and the pump goes into prime mode (kicks to full speed) they will shoot out of the pool. I don't ever turn them on first, just in case the pump does go into priming mode.
You cannot control the 'smoothness' of the water. If you want the amazingly smooth streams, you want laminars, not deck jets. That's actually what I wanted, but I didn't know there was a difference. I still wouldn't run them all the time. I think they may be a little quieter than the deck jets since the pattern is so smooth but pretty sure they are noisy also.
--Jeff