Yeah it's just one episode a set and they vary in length, Vol.1 is 51mins and Vol.3 is 59mins. You get a slip case and some art cards and a little booklet with them but I guess that's only really added value if you care for such things. It annoys me that everything doesn't fit inside the slipcase as it means you need to keep the plastic cover to keep everything together.
As for the quality of the show it self, which is the actual important part I guess, well....I couldn't tell you as I've not seen any of them lol I just bought Vol.1 as it was so cheap on eBay and I loved Code Geass, which meant I had to buy the rest too and because I like to binge watch shows I'm waiting til I have em all before I watch. I'm sure someone else will be able to be more useful and tell you more about the important part.