Originally posted by !~TONY~!
The Benko and the Grunfeld are definitely different. Obviously the Benko is a gambit, and black gives up a pawn. Second, the pawn structure in the Benko and the Grunfeld are pretty much as different as it can physically get. The one thing I like about the Benko is black has alot of great positional trumps to work with. He has 1 pawn island, two open files on the queenside, great dark square control, an outrageously strong bishop on g7, etc...
I love the Benko OTB but for correspondence chess I think a black gambit is dubious (although in most cases i think the gambit is declined now?). I would prefer the Modern Benoni, same sorts of positions with less tactical pitfalls.
the Grunfeld .. almost as much as i hate Alekhine's defense. But this is entirely
a matter of taste, I just don't like breaking the centre, i prefer to fight for it from the start. It certainly isn't an opening for beginners as it requires strong defensive skills (although play it enough and you will learn
all about good defense .. the hard way