TWO posts in ONE day! You so lucky!
So we went, we saw, we were amused.
If you are a Hitch Hikers fan and cannot deal with the idea of one teensy little iota of the book being changed, don't bother seeing it.
If you like the irreverent style of Douglas Adams' books, then go along and watch. Enjoy the show stopper scene "So long and thanks for all the fish." Watch out for the cameos (I am old enough to sorta remember the TV series as well as I remember anything from then) and references to other genre media. It is not faithful to the book but it is in the same sort of style. Somewhat pythonesque really, particularly with the Guide interludes.
And ladies (and gents) there is KNITTING in it! Noone knits, but before normality resumes after one of the Heart of Gold's improbability jumps everyone is knitted! LOL! In the credits, all the people involved in creating the knitting are guys, only I was distracted at the time and can't remember the names (?trevor cooper was in charge of that workshop???).
I think it was worth the $10.50 each we paid using a friends super saver tickets (normally $14.50). So if you are a huge pedantic fan boy, don't bother, but if you are willing to enjoy the ride just sit down and let it happen! Or wait for the DVD.