There are a lot of advantages to shooting with a Nikon, but one of the downsides is that Nikon doesn't make f/4 pro zoom lenses.
For example the Canon f/4 70-200mm zoom:
• costs $600 less than their f/2.8 model
• weighs 1.7 lbs (almost half the weight of their f/2.8 model)
Don't get me wrong, f/2.8 is amazing, but I just don't need it 99% of the time. And if I do need a wide open aperture, I would rather have it in a prime lens that could open up to f/1.8 or f/1.4.
I could also see a real advantage to a f/4 ultra wide zoom (f/4 14-24mm). It would shave several hundred dollars of the price tag, and I never need f/2.8 with an ultra wide lens. Generally I use ultra wide lenses for landscapes and architecture. Both of which usually require deep depth of field.
I'd like to hear other photographers thoughts on this. Thanks!