That would be about the same as saying that the pickpocket situation in Tijuana and San Diego are probably similar because they're so close to each other. Not everyone realizes that there's still an international (like) border between Shenzhen and Hong Kong, and they are very different places.

On my first visit to Hong Kong in 1996, I got a quick lesson in paying attention to my belongings. On the taxi ride from the airport to the hotel, the driver tried to hide one of our suitcases in the side of the trunk so that he could drive off with it without us noticing. Then, inside the hotel, one of our bags disappeared in the confusion of the check-in process and only a big fuss made it magically re-appear.

I know they've worked hard on taxi scams, and I wouldn't expect such a hotel problem at a 3-star or higher hotel, but that was a budget trip. As far as personal safety, I'd rate Hong Kong just about as safe as Tokyo, at least for the tourist. That is, in either city, it's extremely unlikely that you'll run into any problems, and are far more likely to be, say, a robbery victim in your hometown in the US. But as for property, it's a totally different situation between Hong Kong and Tokyo.