garyknrd said:
Looks like both are not near as sharp as the 300mm II lens. Which surprises me.
I don't find that particularly surprising - the 300/2.8 MkI was also sharper than the 500 and 600 MkI lenses. I do find it a bit surprising that the 600 II is slightly sharper than the 500 II - that's a reversal from the MkI rank order.
Also, I wouldn't say 'not near as sharp' - the difference between the 300 II and the 600 II is 2 P-Mpix. Keep in mind that the DxOMark Score isn't a very useful metric, much like the Overall Sensor Score. DxO weights that score based on their priorities. The lens overall score is based on a low-light situation, so the 3.2 Tstops of the 300 II vs. the 4.5 Tstops of the 600 II gives the f/2.8 lens a boost in the overall score.