From OP: "IT's A Post-Processing Engine, so you can view the improvements only on your phone's screen"
So you need to appreciate the difference when you have 2 DHD's next to each other. My household is lucky enough to have just that situation, so I've taken some photos of the phones themselves (left is WITHOUT bravia, right is WITH bravia)
it's actually pretty hard to appreciate the difference in these photos, but in real life there were definite differences. The picture of the kookaburra on the clothes line looked better WITH bravia, the picture of the Coke sign looked better WITHOUT bravia.
I'm happy at least that there's a difference, but it's like someone said a few pages back, it seems like it will depend on which picture you're looking at!
I've also attached the original photos in a zip to download if anyone wants a closer look