Earlier this year we purchased a Streetwalker and a Streetwalker Pro. My wife usually uses the Streetwalker whilst I use the Streetwalker pro. I carry a Canon 5D mkii, Canon 70-200 F2.8L ISii, 14-40 F4L, Sigma 150mm F2.8 Macro, Canon 1.4x Teleconvertor, Filters in Clik Elite pouch, headlight, cloth etc. I find the pack very comfortable to wear for extended periods and not too hot (We live in the Tropics of Northern Australia). I like the hideaway waist strap which makes the pack very comfortable for longer walks. Where the Pro stands out from the std Streetwalker is the depth of the pack, this allows me to stand my shorter lens, including the Sigma 150mm Macro, on end. The Canon 17-40 has the hood fitted and stands on end with ease. I still have room for another smaller lens such as a prime portrait lens such as a 85mm F1.4. My wife like the depth of the Pro so she can carry her wallet on edge as apposed to carrying it laying down jammed against a lens! The D rings on the sho...