I was wondering the same thing....perhaps so but I have not read anything from Sony users about that being an issue.

I think in many cases 12 fps will be adequate but I am very interested to see what the electronic shutter can do for flight images....it perhaps could vary with subject distance as well as the lens and/or use of teleconverters in terms of slowing focus acquisition so the frame rate then suffers too.

Only theorizing of course .... hope to find out all these things for myself soon

I was also surprised at the low light performance.