This is where it becomes really messy. Performance wise, the 9600 GT Sonic is 0% - 10% faster than the 9600 GSO Sonic, which means a stock clocked 9600 GT is going to perform slightly worse than this card in some instances.
Then there is the price; the overclocked Sonic version comes in at a whopping $5 AUD more expensive than the stock 9600 GT. Now, when you put overclocking into consideration at the price point of a stock clocked 9600 GSO, it's going to come in cheaper than the 9600 GT.
So what you have here is a card that is $5 more than a stock clocked 9600 GT, performing at the same speed or slightly faster (depending on the game). You then also get yourself some extra RAM as well.
What's going to be real interesting is the 384MB which comes in $50 AUD cheaper than the 768MB, and significantly cheaper than the 9600 GT. Increase the clocks on the model and you could be onto a real winner of a card if we get performance similar to a 9600 GT 512MB.
Now, I've openly spoken about the issues I've had with NVIDIAs naming schemes, but this has to be the absolute worst. This card has been released because they're dumping the 8800 GS which never sold. The main reason it never sold? No one knew about it. What they've done in the whole process is kill sales on the 9600 GT. Palit are different; their Sonic version of the 9600 GT offers a wealth of connectivity with display port, HDMI and more. But if you're a supplier holding a few hundred/thousand pieces of 9600 GT reference clocked cards, I wouldn't be too happy at the moment.
What makes it even worse is that when speaking to a manufacturer today, they said that NVIDIA are talking about changing the 9600 GT to the GSO. If that happens we could end up with four models under the naming scheme with RAM options being 384MB, 512MB, 768MB and 1GB; and for further confusion there'll also be two different memory widths present.
While this may quickly become one of the best valued cards on the market, it really is the absolute worst thing when it comes to helping people make their decision on which graphics card to buy.
All NVIDIA is doing is confusing everyone and slowing down graphics card professions. They're being slack; the 9600 GSO, while a fantastic product thanks to its performance to price ratio, is just an 8800 GS. Ultimately though, does this really surprise anyone? The whole 9 series have been nothing more than some strategic name changing that does nothing but confuse people. The good news is that cards carrying the X600 GS naming scheme which were generally horrific for games, are actually now really good. So if this is anything to go by, the 10400GS should perform at about the same speed as the 8800 Ultra.