I really have a hate relationship with my Two Little Fishes 150. The elbows are this soft plastic/rubber that leaks if you look at it funny, then as a quick fix comes with a non existent barb fitting, have had problems with it sealing lately and the "filter" is a joke. I have mine on the inside of my sump and am very worried about the ones I see hanging on the outside.
I was just doing a little research for the topic and liked the style of the Via Aqua and that it came with its own pump and was stand alone. Plumbing some of these accessories in, especially those with the el-cheapo fittings, can be a nightmare to find the fittings you need.
The KNOPs look pretty quality, and yes, the Deltec....If they can make a good skimmer......how could they screw that up?
I think there is still a better design out there waiting for this application, possibly a cross through design where the entire chamber is fluidized with some cool baffles to keep it where it belongs.
Oops, now I need to come up with another million dollar idea since I just gave that one away........