There's nothing much wrong with the information in the Souts book.
the main reason why some things were changed in World Builders' Handbook
was to make it _easier_ for world builders.
If, for instance, you want to calculate a world's albedo, Book 6 lets
you do it. WBH gives you a table, in case you DON'T want to HAVE
to calculate it.
Just be very careful if you use BOTH books. Sometimes the WBH formulas
were simplified for ease of use. The formulas in Book 6 are more complicated,
but more accurate (and more flexible, which from a GM's perspective
is _really_ the important point).
John H Bogan