I read it when it came out, GRRM mentioned it on his "not a blog" on live journal back then, and I agree, one of the better newer scifi books written, if not the best. I didn't pick it up until Weir offered it on ePub, prior to that many got to read it for free as he self published chapters on his own website due to being rejected by everyone. Now - film is in production, and it's a best seller. Nice to see a win now and then.
The film could be good as well - after the success of Interstellar in terms of $ and critical acclaim, films of these types are sure on the upswing.