I haven't had a chance to take this bag out on the trail yet, but will be doing so in about a week. I bought this for a Peru trip where the forecast shows significant amounts of rain. It is definitely large enough to hold rain gear, a large DSLR, snacks, water, and other smaller items. I would fully trust that this would keep water out of the main compartment and be comfortable as well. As mentioned, the fabric is pretty rugged and stiff. I'm looking forward to testing it in the rain and not messing with rain covers again!
This review was written in the old system and had content requirements that are different than reviews written today.