Since applying myself in earnest to writing, I concluded that being a writer ruins reading for pleasure.
For example, I pay attention to covers. Does it reflect the story? Which is larger, the author's name or the title? Are there blurbs? If so, who are the blurbs from? Do I find it credible that the blurbing author actually read the book?
I also notice writing techniques that I never would have before. For example, in Jasper Fforde's The Eyre Affair, Thursday Next told the story in first person point of view. Occasionally, there's a break and a third person narrator steps in. Only for a couple of pages. Never the same narrator. Why do that? Wouldn't it be better to either cut the pages or convey the information from Thursday's POV? Why am I even noticing? It was a good read.
While reading All the Numbers by Judy Merrill Larsen, I wanted the story to be first person instead of third. First person would have hurt to read and I cried through the book anyway. But remove that third person layer, even though it was well-done and stayed within third-limited, and it would have drawn me in more as a reader. Instead, I was slightly annoyed by it. It gave me too much tell and not enough show (as in "show, not tell.") But it annoyed the writer in me, not the reader.
While reading JR Ward's Brotherhood of the Black Dagger series, or the three that are released, I was struck by her struggles to make the story "same, but different." It sort of worked, but by the end of the third one, I didn't care about the character because I knew all would be well. They always have been. None of the drama or climaxes made me wonder what would triumph. Of course good would triumph. The Scribe Virgin would intercede to ensure it.
And what is up with the head hopping? Wait...I didn't even know what that meant a few month ago, let alone have it bother me.
I love writing. And reading. For me, the two activities go hand in hand, one improving the other. I delight in seeing a brilliantly executed technique, like Rachel Caine's use of flashbacks in her Weather Warden series. Or the multiple points of view, like in James Patterson's Mary, Mary where the head hopping advanced the story and added to the rising stakes.
But I really hate it when the writer in me gets in the way of enjoying a good book. Or the reader is willing to let the writer get away with some sloppy execution. As with most things in life, moderation.