I will probably post more than you want to read but, I included a picture to help :-D
This is what I had and I found that it disturbed the surface too much. I liked that it disappeared being black and it turned, tilted and has baffles in the output. I switched to a DIY spray bar using soaker hose with holes drilled where I want the water to go.
The issue I see with the lily pipes is that there is next to zero adjustment and when the water has been flowing for a few months the clear plastic will develop a layer of goo on the inside... one more thing to have to clean... although my pipes have the same crud, and they are clear, I don't mind as I can't see them anyway.
I thought that would have had a problem with a layer on the surface and considered using a surface skimmer. Even with the almost zero surface movement now I really don't see any. Pennywort, duckweed and a couple of other plants left floating seem to keep it clear somehow, even where the plants aren't.
Anyway, I wasn't trying to talk you out of them... just playing devil's advocate.
Jeff