down jacket question...

I am looking to get a down jacket for belaying on ice and mixed routes as well as general winter use. My question is whether or not to get DryLoft. My concern is that I will often be leaning/sitting against snow or ice. Does the DryLoft make that big of a difference in terms of water resistance? How about wind resistance? (I assume there is more of a benefit for the wind factor?) I have been looking at the Marmot Parbat & Parbat DryLoft Down Parka. I would appreciate any other input... what do you use, why you do/don't like it.

Thanks,