TweakTown didn't get an early look at the GeForce GTX 690 but today the site offers world's first review of the GeForce GTX 670, you can see how the card performs in this 15-page review. The site isn't on speaking terms with NVIDIA but has good relations with NVIDIA's add-in board partners, they haven't signed an NDA and are therefore free to publish the review well ahead of the official launch.
The reviewer concludes the GTX 670 is an amazing card that will offer serious competition for AMD's Radeon HD 7970.
My personal issues with NVIDIA and the issues that TweakTown on a whole have pushed right aside, the GEFORCE GTX 670 is just an awesome video card that is going to be a serious headache for AMD. The performance of the video card is really quite crazy and the fact that this is the second option for NVIDIA when it comes to single GPU video cards is bad for AMD when it has no issue competing with their strongest option; the HD 7970.