lumberjakeNot sure on the Marmot, but I carried the Nimbus for 1300 miles southbound on the PCT this summer into Fall. It's a good pack. Lots of little pockets if you like pockets. I honestly didn't use the access panel more than 4 time in my 94 days on-trail, but it's always nice to have the choice available. It does pretty well with moisture, so long as your stuff inside in stuff sacks (or a compactor/contractor bag); my sleeping system and clothes stayed dry for the 3.5 weeks it rained in Washington. For what it's worth, I also carried much more gear than the suggested weight and, while a bit uncomfortable (my own choice to let it be), it was more than capable and I never had a rip, tear, or broken strap.