I bought the book on Saturday at lunchtime. As I write this on Sunday night I'm about a third of the way through, and thoroughly enjoying it.
There are moments when I ask, "Seriously, would it be that simple/safe?" and other moments when I ask, "Seriously, would it be that hard/dangerous?" But then, I have none of the skill sets of the characters, so I'm willing to take it on trust that these various activities would pan out the way they do.
Incidentally, what's the angular size of Phobos as seen from the surface of Mars?