It was a favorite English version for centuries, some of that popularity was political correctness -- that it was NOT a Catholic Bible.
I do like some of the language and imagery in it.
One of its strenghths to this day, even in Catholic circles, is the availability of Strong's exhaustive concordance. Even modern word-search software versions do not necessarily exceed the usefulness of Strong's concordance.
I also like the Hebrew and Greek dictionaries.
The american standard version and then more recently the revised standard version were based on KJV. So, thereto, its usefulness is established, even though it is so only indirectly through the more modern versions.