They're a bit worse. I had one international edition math textbook in which numbers in some of the math problems differed from the US edition. I learned this primarily because I bought the US edition "student solutions guide," which is a whole other racket, and the solutions were often slightly different.

Just enough that someone doing those problems out of the book for an assignment would be hosed. It didn't hurt me because my prof assigned his own homework problems, but still, hugely annoying.