Personally, any lens that is too heavy to hand hold is a an automatic pass, so I am always happy to see a lens that "sacrifices" a faster aperture for less weight. And f/5.6 is plenty fast enough. Canon's strategy appears to be to focus on zoom lenses, in some cases replacing primes, and lower weight. That is a huge plus in my book. A minority opinion on this forum, it appears, but I'm guessing a majority of regular non-"forum sophisticates" will agree. Zooms make it so much easier to get and compose bird and wildlife shots (and presumably sports shots as well). Plus, at the wide end, you get shots that you would miss entirely with a 600mm prime, for instance.