Based on the reviews I've skimmed here, I definitely think this is a love it or hate it type of book. Personally, I loved it - it was a quick read, kept me interested, and had me giggling constantly. It's written in a very specific style, which I can see appealing to science geeks who are fans of Joss Whedon, he of the quippy dialogue; as such, I can also see how it might not appeal to everyone. 
 (view spoiler)[For me, the book rang very true, because I am the type of geek to resort to cheap jokes and optimism that borders on stupidity when times are tough. I related pretty strongly to Mark - moments of indulging in laziness and negativity before bouncing right back to gallows humor and getting stuff done. 
 And while I agree that many of the characters were not terribly well-developed, I didn't mind - it felt authentic in a book told primarily from one point of view for us to see them as Mark did. The characters and dialogue are the prime reasons for the Whedon comparison - everyone is sassy and surface-interesting, without a lot of depth - but it worked for me because science was the star here, not the people. 
 Which brings me to the other reason I loved this book - the science! I think Weir did a pretty great job of making it feel realistic while still accessible, so it was believable but not exclusionary. 
 So yeah - if you're a fan of science-y thrillers where it's relatively obvious the protag is unlikely to die despite the dramatic circumstances and you appreciate some snark / borderline childish humor in the vein of Joss Whedon, this might be just the book for you. :) (hide spoiler)]