I like GBII a lot. Nostalgia + my love of SF/supernatural flicks. Sure it may be not as good as the first, but it is valid sequel and it is a good movie in its own right.
The first movie, being, well, the first movie, had the surprise factor and an origin story which pulled the audience into its world. Sequel didn't have that, so maybe, that's why fans do not like it that much.
What I liked in GBII:
- story was OK, it feels smaller and more intimate than the first film which is rare in Hollywood movies.
- both Janos and Vigo were awesome villains. Cheesy but awesome.
- old cast is here, chemistry is intact,
- every scene with the ghosts is cool,
- Statue of Liberty ending was, actually, creative, IMO. Maybe it was a little sappy with all that "happy feelings", but bringing a giant statue to life made it awesome.
What I didn't like:
- rehashes of plot points and gags from the first movie