I'm ploughing through the script - now up to page 73 (of 114) - which puts me just before the triple-whammy finish of Act II. The first Act remains in need of a little trim-down, but Act II and Act III can both easily afford a few extra pages of exploration - which is nice.
The biggest change at the moment is concerning Miller's back story - a certain piece of his past and how it connects with the town itself. It's a bit of a jigsaw puzzle at the moment. You have to find the right points in which to put the right pieces of additional information.
Another thing I'm keeping an eye on throughout this re-drafting is removing/softening anything that could give away anything a bit too soon, be it a plot point, or someone's motivations. It's all a balancing act at the moment, where you are simultaneously viewing the script from afar as one 'finished' piece, and from very close up as you place small bits of this-and-that here-and-there.