Ray you are way off the mark mate and Janus you should really know better....You are both mistaking the image size for the amount of resoluton data the chip outputs.
The Foveon X3 is a TRUE 10.2 megapixel sensor because it has 3.4 million green pixels, 3.4 million red pixels and 3.4 million blue pixels.
A 6.2mp EOS 10D, in comparison, has only 3.1 million green pixels, 1.55 million red pixels and 1.55 million blue pixels.
This means that both the SD9 and SD10 have slightly more green pixels and double the amount of red and blue pixels than an average 6mp Bayer sensored DSLR.
In fact the nearest directly comparable Bayer sensored DSLR is the Canon 11mp EOS 1Ds which has 5.5 million green pixels, but only 2.75 million red pixels and 2.75 million blue pixels.
You also have to pay 5-6 times more for the 1Ds so its not exactly value for money!!!
As you can see, compared with the 1Ds the Siggy SD's both have more red and blue pixels and only have a little less green pixels.
You might think this would help the 1Ds to resolve green detail such as foliage better than the SD's but in practice the opposite occurs due to the sharper image produced by the Foveon X3 sensor.
I have never heard of any Bayer sensored DSLR, whether it be the Canon EOS 1Ds or the Kodak 14N being compared to the resolution of a medium format film camera but I have with the Sigma SD9:http://www.sd9.org/sd9vrsmed.htm
What does this mean in practice?....It means the Foveon X3 endowed cameras can produce huge high quality prints more than double the size that any 6mp Bayer sensored DSLR is capable of:http://forums.dpreview.com/forums....7182672
Oh and if any of you here are into IR photography you should seriously think about getting the SD10 as if you remove the "dust protector" you have probably the worlds most sensitive digital IR camera. (The dust protector is also the the IR filter on the SD10)
Note: this will not work with the SD9 as its IR filter is not removable.