Really good deal. I still have my 102 and use it occasionally when I want to travel light, although the design of it does make it uncomfortable to wear after a while, plus my 70-300 doesn't fit into it.
I bought one of these and haven't looked back. Superb bag:
http://www.amazon.co.uk/Tamrac-5586...ie=UTF8&qid=1394917117&sr=8-1&keywords=tamrac
The problem I have with backpack style bags especially large ones is the inconvenience of having to take them off to access anything. The slingshot will hopefully make it easy for me to capture things quicker by being able to swing it around and remove just the camera. I see it as less of a storage bag like the bag you have and more of a bag that carries only the essentials in a light package. So far it seems to be comfortable but I'm willing to bet that varies with the build of each person.