Interestingly, I see that — often, not always — the other way around. For soundtracks, they feature often very interesting in depth information and material not found elsewhere and quite a few insights, whereas — while I appreciate the booklet in classical recordings — they rarely offer information beyond what is already easily available in various books and concert guides anyway. (Just a generalization, of course.) That doesn’t mean I don’t enjoy good booklets in classical music as well. In pop/rock, informative booklets are the exception to the rule to begin with.