Sequels rarely live up to the original. It's a fact. Sometimes they excel, but more often than not, they fall short. Batman: Year Two is a sequel to Batman: Year One. Different creative team, different approach. And it's a damn fine story.
I'm not the biggest fan of Mike Barr. He's a fine writer, but I don't often take him seriously. He writes fun stuff, but it's mostly fluff to me. However, it's been years since I've read this, so I tried to go in with fresh eyes. And he surprised me. The book isn't the cutesy fluff I'm used to from him. It's straightforward, decent writing. And I enjoyed every bit of it. I guess I didn't realize Alan Davis only drew the first chapter of the story before quitting the book (detailed in the forward). Todd McFarlane stepped in and finished the book off. Alan Davis came back for the sequel to this sequel and both men gave us top notch stuff.
This book collects the original Year Two and the follow up story, Full Circle. Full Circle had a lot of holes in it, but it suspend your disbelief just a little more than normal, it's not a problem.
I don't know how much of this book is still in continuity. My memory gets worse with age, but I don't think much of any of it is canon anymore. It features a lot of Joe Chill and his family. That's the part that I'm not sure fits in with current (or even later pre-New 52) continuity. Things like this change from time to time and I wouldn't be surprised to learn this continuity went out the window two decades ago.
This is a really good and satisfying read. If you haven't read it recently, it's worth picking up.
Batman: Year Two *The 30th Anniversary Deluxe Edition*
Writer: Mike W. Barr
Artist: Alan Davis, Todd McFarlane, Paul Neary, Mark Farmer, Alfredo Alcala, Pablo Marcos