Originally Posted by ueella
The f/2.8 zooms are fantastic in many ways, but they are much, much heavier than their f/4 brothers. A backpack with 17-40 f/4, 24-105 f/4, and 70-200 f/4 is much lighter than 16-35 f/2.8, 24-70 f/2.8, 70-200 f/2.8, and several tubes of Bengay. If you can keep yourself focused on the superior images brought home by the f/2.8, you'll put up with the pain to get it.
I would also suggest that you consider at least one prime lens, even a cheap one. Pick a focal length that you will use often, and get a prime there for under $600. The 100mm f/2 is a good deal and makes a nice focal length for people photography (except headshots), and you will really see the difference from an f/2.8.
Kind regards,