Pros - Leaks, or doesn't allow water through at all.
TWO trips and a half a day messing with these to try to get them to work. The first had a defect that wouldn't allow the water to actually come through....the float was constantly pushed up. The second wouldn't STOP running. Ugh!
Pros - So easy to refill w/out having to take the entire unit apart.
Cons - Still need to clean it.
No drinker is perfect but this one is by far my favorite of the 8 or so I've tried over the years.
The drinking pan does still get dirty from the hens beaks. But I find I an take a brush and swirl it around quickly and dump the dirty water. Then let the unit refill from what's in the tank and refill the tank if necessary. I do this once or twice a week and then once a month or so take the whole unit apart for a good scrubbing.
It does have to be on a level surface. I have mine on two cinder blocks and it's working nicely. Love that I don't have to take the whole unit apart to refill.