Well, high ISO may be important to some, but the difference in DR is not significant: in fact, to my eyes, the A99 has better DR at the lower ISOs I prefer to use. Other features of the A99 are more important. DxO is very subjective, and overly biased for ISO.
2 factors are very important to me: chromatic aberration and clipping. The A99 produces the least of these flaws than any other camera. DxO completely ignores these factors, yet they are the most important for photography. The D800 has a great amount of noise, CA, and clipping. The D600 has less than the D800, but still much more than the A99.
The A99 may be the first digital camera to capture all the nuances of the Zeiss lenses (maybe Leitz too, if a mount adapter can be found). This is a great advancement.