are you able to use the slingshot without having to take off your bag to access your camera & be able to switch lenses?? i'm concerned that things would fall out if you opened the side pocket fully.
The Slingshot 300AW is a lot better for weight distribution because it has a load belt; correctly adjusted almost all the weight is on the hips. I can carry a lot of kit in this all day with no problems, it is large enough to take a 300/4 IS with 1.4X mounted on a 20D. http://www.zen20934.zen.co.uk/photography/mybags.htm#300AW
I still sometimes use my Slingshot 200AW when I am only taking small amounts of kit.
I would be wary of any pack without an effective load belt even if it has two shoulder straps.
As noted early, organise the dividers so the kit can be accessed from the side, it took me a while to wake up and smell the coffee on that one.







