Panny 12-35/2.8 versus Oly 12-40/2.8

[luminescence]

Hi there, I have been looking at these two lenses lately, both very impressive and both rated very closely, as per this report here. I cannot find any other comparison reviews of people who have actually used both. As a GH2/GH3 user I am wondering if there is any disadvantage in going with the Oly; it weighs a good three ounces  more than the Panny, with more fancy lens elements, but don't know if it makes it necessarily superior to the Panny. It certainly 'feels' like a better lens and happens to be much cheaper. Anyone  had experience with both?

[nigelbb]

A big difference is that the Panasonic has image stabilisation built into the lens whereas there is none in the Olympus as they don't need it as they have that amazing 5-way stabilisation built into their cameras.