High Intensity Storylines - Engaging or Overwhelming?

In October I heard Julianna Baggott give the keynote speech at the "Push to Publish" workshop and loved her take on creative efficiency (down with word count as a measure of creative output!). After the talk, I purchased a copy of Pure, the first book in Ms. Baggott's Pure Trilogy, "a post-apocalyptic, dystopian thriller and love story."

I finished Pure last night and there is much to admire about it. Ms. Baggott has a wonderful flair for description ("The skies were buckling with dark banks of blackened cloud..."). She also has an ingenious mind for plot devices, such as the fact that during The Detonations (a specter of Hiroshima and Nagasaki), people fused with inanimate objects and even other people, often with horrifying results. There is one especially affecting scene involving a man and a car.

However, I don't think I'll be moving on to Book 2 of the Trilogy. Ms. Baggott kept the story in Pure at such a heightened intensity throughout that I became exhausted by it. The plot galloped from one harrowing event to the next with little exploration of the effects of those events on the characters. The man-fused-with-car scene, and its surrounding characters and story, could have been a book on its own. By the end, I had become numb to scenes that should have packed an emotional wallop. I would have found the book more satisfying if Ms. Baggott hadn't cast her storytelling net quite so wide, and hadn't focused quite so relentlessly on the gory extremes of human experience.

Pure has won a slew of accolades so it's clearly not a matter of the writer's skill but rather of the reader's preference. So my question to you is ...

What is an example of a book that packs a lot of high intensity material into its plot, and did you find it engaging or overwhelming?

Cheers!
Matty