There was a large group - nine of us in total. Andy was seeing it for a second time to study the special effects, I think everyone else was seeing it for a first time. Although it is long (2:30?) it didn't drag. The invisibility cloak was done very well, and the owls were good - they switched between real and (I think) computer generated ones and I for one couldn't see the joins. Kim said that the actor playing Harry Potter had his voice break half way through filming and that his voice was dubbed for half of the picture but I couldn't detect it.
I think everyone enjoyed it - I'd recommend it if you haven't seen it yet, or if you feel like going again.
Right I'm off to bed. Have fun you-all :)