If the title carries meaning for you, you are, arguably, the intended
audience.
I found the main story to be a fun little meta-fictive romp, and not a
lot else. In tone it very much reminded me of his earlier novel, Agent
to the Stars--deeply aware of, if only to have fun with, genre
conventions. As utterly unconcerned with the "science" part of "science
fiction" as its purported source material.
There are certainly far worse ways to spend a few hours, though there
are many better ones as well.
I was intrigued, though, by the three "codas". Obviously, John felt it
necessary to write a little apologia for it. And I was doubly
intrigued when a review I read of the book a couple of days before I
got to it myself suggested that the codas were a waste of time.
In fact, I think the codas--specifically, the second coda--are the best
part.
Now my gut reaction to writing in the second person is something in the
general neighborhood of derision. Tell me you're doing it, and I will
suggest you are making a mistake. Tell me you've already done it, and I
will make a note to avoid your book. Admittedly, if you get me to read
your book anyway, and I might actually like it (thank you, Mr.
Palahniuk), but my default assumption is that it is going to be annoying
and precious.
But I can't imagine the second coda to Redshirts working as well from
any other point of view. To ask the reader--especially one who has some
idea what might be coming--to empathise with the weirdness of the
situation the character finds himself in pretty much demands something
as jarring and weird and annoying as second person narration. So I think
it not only worked, but was the only way it could work. So I actually
found myself more satisfied after the codas than before.
I'll note, just because I've started paying a little more attention to
this in my fictional choices, that I believe the book fails the Bechdel
Test. I think there are only two female characters in the whole thing,
and they never talk that I remember. Just so you know.