Pros: Easy to fill
Cons: Can't see water level
I had been using the plastic type 5 gallon waterers, but my grip is failing and I had a hard time opening those. On top of that, I get wet capping the outlet and uncapping it, and backwash pulls waste into the tank. I saw one of these vaccum seal ones, and got it to try. So much easier to open and fill. Only downside is that I can't see the water level, but that's not a big issue. It only takes a moment to check them. An additional bonus is they don't backwash into the tank like the plastic ones do, so the water stays cleaner. I'll be slowly replacing all of them. In the meantime, my other half maintains the harder-to-use screw top ones.