Cage free versus battery can be massive. And it depends on whether the chickens are allowed outside to roam (as I said, free range) or whether they are barn chickens, who are kept inside. Free range find their own food, barn are better from a welfare point of view but are being fed on what battery chickens are.

I buy supermarket eggs out of necessity, and buy better welfare ones. But for taste, as ysolde highlights, get ye to a farmer's market or farm shop and buy some eggs from chickens which wander, find their own food. The yolks are vibrant and they taste of eggs. You can tell the difference, even if you don't know where the eggs came from (I went out for breakfast with friends at the weekend and their poached eggs were sourced well - a dark intense gold, and tasting so yum).

We did come close to walking out the restaurant because they said there would be a 20 min wait for a table.. but I'm glad we didn't. All around good breakfast. I also don't recall having walked out once food has arrived, but I have left a restaurant when they kept us waiting too long for the order to be taken.