Me neither (don't use them), but they do have a proper support. Take a look at offerings from Lowepro or Tamrac, I ended up with Tamrac 5793, it's small enough to take for a bike ride and fits the 600 with pro body attached.
The Tamrac is nice if you only need to carry the 600. Most of the time I have other lenses or another body with me plus flash if needed. I usually put a white towel under the lens so I have it if I need it. The gura gear bag has padding and a back pack harness on the back side. It offers as much protection as any other soft sided bag. The good part is it will fit in all airplanes over head bins and can carry lots of other gear. My gear is insured in case something beyond my control occurs. I buy my equipment to use it and insure it in case the unfortunate happens.