It's definitely a trade-off with the weight, but one I'm willing to make. When I'm hunting I can control what I'm doing to a certain extent, but there are times when I just need to haul ass and not stop to adjust what I'm wearing. Or, times when I'm climbing and need to take a short break, but don't want to take the pack off, dig layers out, and layer up when I'm going to be moving again in five minutes.
