totally agree for a shrimp tank they are amazing filters. shrimp make very little waste and the amount of grazing space for the shrimp is huge.
the only real downside of these is the look. I dont run one on my fissidens tank because its so beautiful to look at, but I do have a small shrimp breeding tank with a HMF powered by small return pump. basically its like those little prefilter sponges on and intake, but about 100Xs bigger and no need to clean it.
I have my planted nano tank with WCM's, and neons, I have my big planted platy tank, so I don't need all my tanks to have lush green forests. Shrimp tanks are for shrimp and breeding, so whats suited to them, I don't about the look as much when I have the planted tanks I already want.