I was initially impressed with Final Draft 8 - until I started using it regularly. I have never known a program have so many irritating faults - and create so many corrupt files. It's ridiculous - it's basically Word with some macros added in, but it is riddled with bugs, and is incredibly frustrating to use. I think it's a disgrace that it costs so much money, and is so completely, fundamentally flawed.
I can't count the number of files that have suddenly become 'corrupted' by Final Draft and then won't open. If you do buy this program - and I strongly advise you not to - make sure you save every single change you make into another format, so you can rescue your script later when Final Draft inevitably crashes.
The so-called automatic backup feature is next to useless - why bother automatically backing up files that Final Draft has itself corrupted?
There are plenty of other, free programs on the internet that do exactly the same job (Citrix for example). Save your money - and your sanity! - and steer well clear of this expensive, over-hyped mess.