The first Police Story was Jackie Chan's favorite of his movies, and it's a good one, to be sure. Police Story 3, which goes by Supercop, is my favorite of the series, mostly because of the awesome Michelle Yeoh. Police Story 2 falls in the middle, not just in the order they were made, but in the quality it offers. It's passable, with a couple of Chan's set pieces, as usual, but it falls far short of the other two.
First, to address some confusing matters, there are several different versions of Police Story 2 out there. (This is often the case with Hong Kong films when they are released to the American market.) For brevity, I'll stick to the two basic versions on the Criterion Blu-ray, the original Hong Kong version and the longer version ... not sure what to call it, to be honest. That version gets a 4K restoration from Criterion, while the original, which is presented as an extra on the Blu-ray, is "a new digital transfer of the Hong Kong-release version of Police Story 2 ... created in 2K resolution from a subtitled 35mm print supplied by the American Genre Film Archive. The transfer is presented with minimal restoration, leaving scratches and damaged and missing frames intact, to convey the character of the film element." I didn't want to watch a scratchy print with burned-in subtitles, so I opted for the longer one. Also, the people I was with wanted the English-dub, which didn't suck, but which resulted in things like Chan's character, Chan Ka Kui, being called "Jackie Chan".
Most of Police Story 2 is, well, kinda boring. Chan movies always revolve around the set pieces, but there are only two memorable ones in this two-hour version, so there are some dry spells. Those set pieces are classic, no problem there.
Also, the great Maggie Cheung is less annoying here than she was in PS1 and PS3. She also fell victim to something Chan goes through in virtually every movie: she got hurt in a stunt, bad enough that she couldn't finish the movie (her part was played by a different actress who didn't show her face).
Police Story 2 is not the place to start if you want to see what all the hubbub is about Jackie Chan. I'd go with either of the other Police Story movies, either of the Drunker Master movies, or maybe Armour of God 2: Operation Condor (which goes by many names). If you are an American, I'd go with Supercop.