Speaking as a professional nature and commercial photographer, it's perfect for traveling in any mode of transportation!
Purchased this for use with Nikon D200, 18-200 lens, SB-800 flash. That's about all it will hold at any given time - plus spare battery and cards in the front pocket. The interior is infinitely configurable - but not easily changed due to the large amount of velcro - it's good because it stays put - but a bit frustrating at first set up. The diameter of the Nikon lens shade made it a bit difficult to get it in and out - but it did fit. Carried for several days on overseas trip and was happy with comfort.