I'd also like to know who uses the computer based software version apposed to the website
Me.
what is the benefit?
More than one benefit ... The web one is a crock of crap. Everything that Bloggs said, plus the computer based one is much better at handling errors. It lets you know that you did something daft and allows you fix to it and re-submit, rather than making you start again from the beginning like the web one often does. Bloody frustrating when you've just put in a multi-stage plan ! And how daft is it that the web one asks you how many stages you want beforehand ? Very lazy programming from someone ...