I purchased this camera bag in medium size to fill in my Travel Backpack 45L. This bag fit quite well with the Travel Backpack. In addition, the space in this bag is quite large and can hold a lot of camera's accessories.
I use a backpack and a wheeled carry on for my equipment. When I am traveling locally or over seas, this cube has been a life saving piece for my equipment. It all stays in place, there are enough compartments for everything, plus the dividers are removable in case you need to accommodate equipment. And the outside straps and hooks make it easy to secure or pull the cube when needed. In my medium cube, I am able to carry a full frame body, a mirrorless body, 4 lenses, two flashes, accessories, flash cards and extra batteries. I am sold!
I bought the small camera cube to go along with the Travel Backpack , a tech pouch, and a medium packing cube. Not only does the small camera cube fit all my portable gear, it works wonderful within the system of the travel backpack. The U-Clips helped keep the camera cube in the backpack secure and when attaching the quick release clips to the end of the cube, I use it as a daily camera bag with a Peak Design strap. The dividers, pocket and all the space inside is plenty for a mirrorless setup. Even if I upgraded to full frame, it wouldn't doubt if I needed the bigger camera bag. The small camera cube is perfect for daily carry and for the travel backpack if you need clothes and other tech in the other space.
I purchased this cube to hole my full frame body, lenses, and accessories. I am very pleased with the quality of the material and construction of this bag. I especially like the ability to customize the slots with the flexfold dividers - great idea. I will purchase another one for my mirrorless setup. You've got me sold!
The materials are superb and the construction is solid. I use it to store my gear and with my F-Stop bag for some hiking trip. I use a lot of PD bags and accessories and they are all good quality and this one is not a exception.
I have got the Travel Backpack with the full kit on Kickstarter and I couldn't be happier, I have used to travel and for wildlife photography. I have got a medium camera cube and I am going to get a small as well when I don't need all my stuff with me. In the medium camera cube I can fit (keeping the backside pocket capability): my Nikon D500 with a 100m on, a Nikon 200-500m, a 35 mm, and there is still space either for 1 big lens (like a 70-200) or 2 medium (like 2 24-70) or 4 small (like max a 50mm), I could imagine why you need more than these, I guess instead of this extra lenses you could fit a Mavik Pro with accessories with no problem. Hope this helps.
The small cube holds two chargers, two mirrorless bodies, seven lenses, and cleaning equipment. Or at least that's what I put in it for my first trip with it (A7Rii with 35 and 85mm lenses, and an OM-D E-M10ii with 20, 12-40, 60, 75, and 40-150mm lenses, both cameras with a handful of batteries, dual battery chargers, and cleaning cloth, lens pen, and dust blower). The shelf dividers are great (and the secret to cramming this thing full without having lenses grinding together), and I carried the kit around with a PD Slide strap quite comfortably. I haven't even test-packed the medium size cube I bought, and I'm glad that I didn't get the large, because I don't ever need to carry that much kit!