Strangely enough, I didn't enjoy this viewing as much as I hoped to.
I couldn't warm up too much to Hepburn and Stewart, her seeming a bit too cold and distant and Stewart being a bit over the top at all times. I was really amazed by Grant's performance, he really is a master of comedic timing - although once in a while there was a little help from the editing room.
There were a couple of really funny scenes, my favorite being the opening shot with this totally absurd act of violence of Grant's character towards Hepburn. The side characters had not enough definition for me, especially the mother and Uncle Willy, I would have loved to see them more absurd, like in "The Lady Eve", where everybody is totally over the top.
I could also strongly feel the theatrical character of the play shining through very often. There are often situations where the characters just sort of line up in the frame and there I felt a lack of spatial experience.