Okay, went to see the movie last night.
Enjoyable and engaging. I had no problem staying awake throughout, even though the session started at 9.20pm and I'd had only a few hours sleep the night before.
But sometimes I felt it lacked emotion. Compared to Ed Harris's Gene Kranz in "Apollo 13" wearing his heart on his sleeve, many of the NASA characters in "The Martian" come across as bored rather than inspired by the part they're playing in the manned exploration of Mars (or the rescue of Watney): Teddy the Director, Bruce Ng, Mitch Henderson and to a lesser extent Vincent (and Kristen Wiig seemed to be channelling Allison Janney's character from "The West Wing"). Also the five surviving astronauts seemed a little emotionless during their own launch, despite the sudden loss of Watney and their own narrow escape. It seems to take the crowd shots to set the emotional mood in tense scenes. Lastly, the post-rescue scenes of Watney on Earth seemed a little anti-climactic.
But there was plenty to like too: I enjoyed feeling as well as hearing and seeing the MAV launches (I watched a Shuttle launch filmed from close-up at an IMAX cinema so it was good to experience that effect re-created). I liked the portrayal of the Hermes and the changes from the weightless spine to the rotating habitats. And I thought the Rover and all the spacecraft had a realistic solidity about them. Plus I enjoyed the moments of humour (Purnell doing the banana-skin gag on loose papers on the floor, Annie Montrose so not getting the LotR references and then objecting when the spacecraft-pen touches down on her head, the many jokes at the expense of disco music). And overall I just enjoyed the scientific solidity of it all (even if they essentially ignored the effect of Mars's lower gravity as Watney moved around in the Hab).
Oh, and are mountains on Mars anything like those in the movie? And could an astronaut make his way around the outside of a spacecraft which was accelerating with an ion drive?