Turnstyle 10 fits my Nikon D600 with 24-85mm attached + any one lens such as Nikon 18-35G or Tokina 100mm 2.8 macro with some room left. It's the first sling bag that I could actually use without my shoulders killing me. The fact that it's left-shoulder sling if preferred for my personal use. You can also fit Nikon D600 with Nikon 70-200 f4 but that would be it. It's not really workable as waist bag but my be used as such if your shoulders are tired. Another advantage is the build-in rain cover which is a nice addition. Lobe lots of space in front for your wallet and phone and zipped pocket for small tablet (ipad mini will fit).
I do have 3 Kata backpacks which are grate but since those are bulky I noticed I was not taking my equipment out. While with this one it's so small I grab it every time I'm out and about.