I use a bottle style waterer inside the coop, and a regular fountain style chicken waterer outside of the coop. The bottle style waterer I use is the Water Buddy by Edstrom. While it holds only about 32 oz, the outdoor waterer is several gallons. I believe that they are discontinuing the Water Buddy model soon, which is too bad, since I have had no leakage from the spout (as opposed to ball-style waterers, which always seem drippy). It's also top-fill, which is very convenient, and the water stays very clean.
The chickens have had no issues learning how to use it, and the water level changes make it obvious that they are using it relatively often. It is keeping the coop much drier (and therefore cleaner) than when I had a larger waterer inside the coop (which kept getting bumped and spilled). They even make a Water Buddy with a plug-in heating element to keep it from freezing in the winter (I have both the heated and unheated styles, so I can switch them out).
Since the bottle waterer does seem to make the chickens work a little harder to get water out, I'm glad that I have both the bottle waterer and the fountain waterer. I don't worry about them getting dehydrated as much, having the multiple choices available to them.