Olaf wrote an answer about Mammut Eigerjoch Down Jacket - Men's on December 24, 2013
800 Fill is the measure of quality of the feathers not the weight. You are looking for an answer in grams and not Fill. For example the lighter Rab Neutrino Endurance is a 625 gram jacket that has 225 grams of feathers while the heavier bulkier Rab Neutrino Plus is a 760 gram jacket that has 275 grams of feathers. Because this Eigerjoch is a 710 gram total weight jacket with the same 800 fill quality feathers as the Rab jackets it should have a fill weight of around 250 grams or somewhere between 225 and 275. So it would be comparable to the Rab Endurance Plus for warmth but feels lighter on your back.