Domke x 4
I have a 40 year old collection of camera bags, backpack, two hip bags, including about 20 Tarmac, Lowepro, Domke, and others. In the last few years I have ONLY chosen the Domkes only.
I have three Domke bags, F2, F6, and F3X. I choose the bag based on the equipment I need. I can take up to two DSLRs with L plates attached, six lenses (depending on size), 12 filters, lightmeter, cleaning kit, green "the pod" with qr receiver attached, and small books with a kindle in the back pocket. They are the most comfortable to carry by a large margin. Like any bag greater weight weighs you down. They are very rugged. They have a short handle to carry them by when not worn over your shoulder.
They are waterproof to a large extent. The main flap covers the main pocket with extra material overlapping the sides. The fabric is a very thick cotton canvas that repels water. It might start to saturate the fabric if out in a heavy downpour for more than an hour.
Counter intuitively, the regular canvas bags are heavier duty than the "rugged wear" ones.