I read the van Gulik novels decades ago. I thought they were great. I have no idea if the Chinese tales on which the characters were based are any good, but van Gulik was a master at creating interesting characters with an exotic slant, as it were. Sometimes, the chinoiserie is better than the original. Obviously he was a sinologist, and writing the novels was more a hobby than anything else, but I think he could have segued into regular detective novels or police procedurals that would have reached a wider audience. Nonetheless, the Judge Dee works were an interesting departure from Raymond Chandler, Dashiell Hammett and Joseph Wambaugh.
Van Gulik died in his 50's. Here's a pic of him decked out in what I'm guessing is a facsimile of Qing dynasty leather armor:
van Gulik was a professor at U of Chicago, where both mother and I went to school, at different times than when he was there. But the connection made it more fun for us.
I still own all the books and reread them occasionally. Every now and then I get a sense that the application of justice is similar in Guardian. I still remember the chests for the various seasons of clothes, and the weather proofed umbrella. I bought the movie and it was awful. They lost the cultural descriptions that made it of high moral character and turned it into a kungfu fighting movie. Guardian keeps the character.