We used them for the first time this yr..  Liked them very much, and as said nice not to have all the metal hanging on the planter.  for liquid n, used both tubes on either side of the row about 2-3 inches or so, but some we just put starter on, and put it down one tube almost on top of the row.  Don't know for sure if that is the thing to do. 

Also thought it would catch more stuff or somehow ball up, but we hardly noticed they were there.  Had one hose break as I think now, but repaired in no time as it is out in the open. 

 Dry year might be different, as we were very wet this spring.  We have clay soils that pack easy, and getting rid of the 2x2 actully help our stand and sidewall compation issues.