North Face Twin Peaks 2 person sleeping bag

So as of today Jane and I have 2 fairly light 15 degree bags. I have a mountain hardware bag and she has a north face. Both are 15 degree and both are goose down. We are contemplating the Twin Peaks. It is almost a full pound heavier but that being said it is only 5 pounds and we would be in the same bag attune same time. It's rated at 20 degrees but I also figure that we would be generating more body heat and it might even be more like a 10 degree in a lot of respects. I can't really find a flaw with this idea yet. It's a synthetic down fill but I don't really care about that. The weight isn't an issue. We won't ever be separated on the trip so it's done we only have one bag. They are also on sale for the low price of 99$ at Cabelas .com I need to read some reviews from people.