For each of these pictures, the top one is all automatic settings, the middle one is with optimization turned off, and the bottom one is HDR. I'm running firmware 2.17.40 (received this morning).
This one is much better with HDR. Between Optimization auto/off, the top one seems better to me.
Again, this one is much better with HDR. Between Optimization auto/off, the top one seems better to me.
For this one, HDR is too washed out. The top one, automatic optimization, seems better to me but some might disagree.
And finally, for this one, I honestly can't tell which is better. Out of the 3, the top one is the one I prefer the least. The blacks look too black.
As far as I can see, there is not one setting better then the other, it all depends on the subject matter. If the picture's subject is darker colours, HDR wins. If colours are lighter, automatic optimization may be better.