I have had the larger of these for around a year. The inserts are of the "padded box with velcro dividers" design. In the main cavity, within the box and it's dividers, I fit, 55 -200 VR zoom, D3100 with fitted 18-55, 35mm prime, YN flash, (about the same size as a SB-800). The bag has small pockets at either end, a zip pocket inside and a single large side pocket. In one small pocket I have a Rocket Blower a lens pen and the usual half a dozen lens cloths, in the other small pocket lives a notepad and few pens. In the front pocket, (this is so hard to type - my nine month old son is trying to grab the laptop and attacking me), lives a couple of those cheap filter pouches, some wireless flash triggers, spare flash batteries.
The bag has no lining and is in no way weather proof. I have the box insert thing stuffed into a big John Lewis plastic bag, just in case I get caught in a downpour. It is fairly easy to carry in a gym bag way but the canvas strap does creak a bit.