The other commenter said that it's a joy to read and that's certainly true. If you're interested in software folk tales and such, it's worth getting.
I still see it recommended as a practical book however and indeed the book bills itself as "the second book you need on C", the book that will cover topics that other C books don't explain or explain poorly. But it's much too outdated to serve that purpose. In practice it means chapters discussing differences between K&R C and ANSI C and deep-dives into details of SunOS and MS-DOS compilers.
Some of the material has become misleading because the C language has evolved. For example, there's a lot of discussion about pointers and arrays, as can be expected. But there's no mention of strict aliasing and pointer provenance (these rules existed in C89, but compilers at the time didn't exploit them yet for optimization). And of course no variable-length arrays (introduced in C99). So you're not going to learn what you need to know in today's world.
The book also has almost no discussion about safety. The Morris worm is mentioned, but just as a piece of historical trivia. Browsing it now, I don't even find any discussion about buffer overflows.