When I had it mine hooked up to directly to a maxijet it worked great, it definitely cuts down on the flow, but you have to remember they can barely handle any real flow.
I tried to use it on my return line which was mag 5 from my sump split into two and one rotated and would stop while the other would just kept getting stuck, I also modded them to screw directly into my bulk heads to avoid popping off but that didn't prevent them from stopping.
I changed and just used a SCWD and have had no problems at all. They are cheap to buy but they are cheaply made too.
