Well, it's not as bad as it sounds. Even lots of clothes for her don't weigh a lot since they are small. The Peapod weighs in at just less than 3lbs, which sounds like a lot until you realize that a pack n play weighs 25lbs
we haven't done much true backpacking with her, but I think it's doable. My goal for next season is to get her sleeping without the Peapod so we can leave it at home.
If you plan to take a baby, my best advice is to try naps and even overnights at home in the same sleep system. We started Molly napping in her Peapod at 3 weeks old. It's definitely helped her adjust to sleeping in different locales. We've used it in cabins, tents, hotels and other people's houses. The few times I have tried to do without it she didn't sleep well, so it's 3lbs of worth it for us.