Howdy,
Wanted to say hi and give my input. I have run the nyos 160 for years. I agree w everything Brad said except the dial in. (But that was just my experience)
I was running a Vertex prior so I may be spoiled. The Nyos build is on par with the vertex. My issue came in the adjustment. I ran it as an air pump for 2 years because I could never get it right. It was always overflowing or not producing bubbles. Since I have it figured out last couple years it is great. I am 100% Nyos fan now, just very annoying at the begging.
I like the Nyos because it is dead quiet, I like the pump is internal, and the body is abs. The Octo I hear is really good too..