Ok, mandatory comment:
The reason you find Canons more intuitive, is that you're used to it. Both Nikon and Canon have excellent setups and its all a matter of what you're used to.
As for ergonomics, as I said, I like Nikons better, many do not. We're all different, and thats why there is a market for more then one manufacturer.
Ok, on towards your question:
I have a 17-55 f/2.8 and it is by far my most used lens. With that said, I really really want a 24-70 f/2.8.
The cons are;
1. It is alot more expencive (about twice the price)
2. It's almost double the weight.
As for IS, I don't have VR on my 17-55, and I don't miss it. However, 70mm is a bit more tele. In practice that means you're going from 1/60th of a second to 1/70th of a second as slowest shuttertime for handheld pictures.
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I has a flavor!
CC always welcome.