If you're reading this review, then you should already know what you're in for with Code Geass, so I'm going to skip over a few parts (like art and sound).
Story 10/10: Possibly the biggest complaint you'll heard about the story of R2 is that it's the exact same thing as the first season, which probably means the people with that complaint didn't get through the whole series. It will seem like they are repeating everything at first, but that is because with Zero reemerging he needs to establish himself as the real deal. After those first couple episodes, Lelouch hits the ground running and gets right back to working towards obliterating Britannia. If you think you may get disinterested from this continuing story, don't worry, that won't be an issue by the halfway point.
Character 10/10: All unfinished character development is taken care of in R2, and even the new characters introduced have time to become well developed. Motives become clearer, friends become enemies, enemies become friends, your heart gets broken, just another day at the office.
Enjoyment 10/10: Same thing I said in my review of the first season, I've watched Code Geass and R2 at least 10 times each, so of course I enjoyed it.
Overall 10/10: After the final episode aired, I didn't know what to do with myself; I would watch the episode again every morning before going to school for the longest time, just to start the day with a sense of wholeness.
The reason this show holds so much importance to me is because it really helped me out during a down time in my life by getting the lesson through to me that you can't dwell in the past, or only live in the present, but to always keep the future in mind. I hope it can do the same for everyone else who watches it.