"Science aside, the first half of the book was interesting and entertaining character development and backstory. The second half really sucks you in and becomes exciting and suspenseful."
On reading the first part of that second sentence, "The second half really sucks," my heart fell just about to my feet. My tear ducts sat up and said, "Hello!" I actually had to read it again to realize the reviewer liked it.
We writers are such an emotional lot, aren't we?