Hong Kong cut this time. The short added fight in the gym is fun. The additional storyline with Sally Yeh is OK, but it makes the film feel more disjointed than it should.
What really sets this apart is the reshot/re-edited end fight with Bill "Superfoot" Wallace. In the US version it's such a slow, disappointing fight that doesn't do justice to Jackie at all. He's just getting beat up for most of it. The HK version is much faster and the added bits make it so much more meaty and exciting.
Overall, I wish there was a composite version of the two edits.
There's just something about these Spy Kids movies that makes me feel like a kid again. I love how imaginative they are, and how much the series embraces the "anything goes" style of kids playing around. This one feels a bit different because it's just the one kid for most the movie, but it's got Stallone so I have no complaints about anything.