As far as ease of use, our automatic watering system with nipples on the cages and a 5-gallon bucket is my favorite. We plan on switching to almost all automatic watering system for the warm months.
Having said that, when we bought cages and supplies (and rabbits) from a rabbitry that was closing, they came with the Lixit glass bottles and the mounting brackets for the cages. By far, they are my favorite of any other water bottle we have used. We didn't have them through all of winter, but through some colder 20-30 degree days. Granted, where they were didn't seem to get as cold as the outside temperature (garage shelter, no heat) but nothing froze.
The only reason why I like the automatic watering system better is that the water lasts longer. Otherwise, I highly recommend the glass, and eventually we want to switch all of our cages to the glass bottles for at least parts of the year.
Forgot to add that Klubertanz sells the Lixit bottles with the mounting brackets. They aren't cheap, but they sure are durable. The glass is THICK too.