I use the dart for a closed loop.
Cant see any pumps hanging in the tank.
Flow??
a lot
The way my nozzles are set they hit each other and the flow becomes random.
True you can see how the coral grows and notice the water pattern by the growth but for me that adds character to the tank.
The only thing I will add in the future is some sea swirls.
Thought I'd post a little about these eductors, certain requirements for them to work well but yes, you can stir the pot very well with these, I'd recommend reflecting them off something to ease the spread unless your going across a long distance, I even have there directions to make your own & you can tweak it to fit your tank needs.
BTW eductors have been used many years in our hobby, mainly in long or larger tanks because of how they work, BTW this reminds me that I've been wanting to make one for a long time now