So how much is 1/3 stop of light loss? Samples!

The SLT cameras are said to lose 1/3 stop of light due to the translucent mirror. Here are 3 images taken at ISO 3200, with the 18-50 mm lens at 50 mm and f:8.

They are 100 % crops from jpg files straight out of the camera. The images are adjusted to about the same brightness. No noise reduction is applied, just a bit unsharp mask to make the noise pattern more visible.

A = correct exposure
B = 1/3 stop brighter exposure (equivalent to no mirror at ISO 3200)
C = 1/2 stop brighter exposure

Now, tell me which is A, B and C!

Then tell me which real world situations the 1/3 stop difference in sensitivity would make a photograph useless or not.