I've realised more recently that I have a real preference for how roleplaying books read. Although layout is important and I don't notice pictures except by their absence (unless it's a bestiary), I find that the books that hold my attention are the ones that write in a flavourful, succinct and precise manner - a hard combination to be sure.
I've found that Blood & Smoke is an easy read because each section clearly states what it needs it to say and does so through the use of rich analogies that also helps it paint a consistent picture of the game, style, and roleplay experience on offer. Therefore reading it gives you not only a firm view of the rules but an equally full comprehension of what being a vampire feels like -- which is great because another culture's / creature's psychology is far harder to understand than a few basic rules!
On the other hand, I've found some of Trail of Cthulhu rulebooks a bit dry because it's rules are so quick, rapid and summative that my eyes glaze. Ironically enough sometimes you need a few extra words to be succinct in a way that captures attentions and allows additional clarity.
Does this mean I dislike the Trail of Cthulhu books? Not at all. There are parts that are rich in analogy and I love how they include extra details like clues left behind by monsters. I just have a preference for Blood & Smoke (though not all White Wolf books - some are waaaaaaay too lengthy and spend an entire book belabouring a couple points).
I'm wondering how Call of Cthulhu 7th edition will go? I liked the 6th edition book well enough, though I didn't find it mesmerising it was a solid read. Hopefully it is an even better read!