Well, I feel fairly qualified to address this, since I've had both, with the BFGs on several different cars from FWD import coupes to classic Mustangs.
The G-Force Sports are an incredible tire. Sticky (beyond the limits of what I've mounted them on), great steering response, excellent in the wet, very "communicative" when pushed, and above all, VERY affordable. I've seen more than one vintage Shelby running them on track events.
Their downside is weight, rough ride, and road noise. Very loud tire, even on cars of several different layouts and weights (see above).
That said, I've just picked up a set of the Direzzas a couple of months ago, and have been extremely impressed so far. Handling is superb (though with a bit more quick breakaway than I like at the limit, but that's being pushed quite hard), steering response is razor-like, (have not yet had them in wet, so can't comment there), and they've been VERY quiet - so I'm not sure what the comments about noise are, other than that may be something awaiting me in the future - and an extremely smooth-riding tire.
How's that to confuse you more???