As far as I know the revised books have not made major changes to the books (they have left Wainwrights words and pictures), but all the walks have been checked, and maps and text updated, parking info added etc.
But I guess it depends how you are going to use them.
f you need them to do the walks NOW then buy the updated books, if you want them for general reference and to read at home on dark winter nights buy the originals.
Better still buy one of each set
£56 for the updated set
http://www.amazon.co....itions/dp/0711232717/
£51 for the original set
http://www.amazon.co....wright/dp/0711224617/
So just over £100 for what in my eyes are a work of art and a tribute to one mans love of the Lake District.
Wainwright is somewhat of a hero of mine and these books are wonderful. Each page has a little gem such as some fine words, or a little joke, or a lovely small picture.
Se the drawing of the top of Coniston where he shows all the ladies in high heels and the boy scouts pointing towards Blackpool tower, while the lone walker is looking over to the fells. Stunning stuff.