I read Redshirts in a combination of audiobook - narrated by Wil Wheaton - and paperback, purchased and signed by John Scalzi at last month's Supanova in Melbourne.
As Scalzi himself noted in the Coode Street Podcast, he's improved his use of dialogue tags (he said, she said) in response to his awareness of how these things sound in audiobooks. Which, yay - because the tags were driving me mad when I was listening to the audiobook. I did vaguely notice the difference in Lock-In, although I wasn't listening to that one.
As to the story. Redshirts won the Hugo Award in its year, and a lot of people dislike that fact. I can't compare the book to the other nominees that year, and I can totally imagine than there were better books - I'm certainly not saying that Redshirts is flawless. But it operates on so many levels of surface, cynicism, and deep love of the genre. It's good. It's inventive and fascinating and really thoughtful. And it knows it, which, you know.
But yes, I totally recommend it, especially for snarky Trek fans.