This is something I always wanted to see, but the review is lacking. Should compare it against a stock/normal HD 4670 with GDDR3. And from what I can see, GDDR4 can run a bit faster than 1100Mhz, would've been nice if it were clocked at 1200Mhz or so stock (read: better GDDR4). I can hit 1100Mhz with my GDDR3 version.
But really, who reviews a video card with one thing "new" and doesn't include the stock version?