I like primes, too, but I don't like changing lenses, carrying a bag full of them, and camera shake.
I like to shoot in dodgy light, but I don't like messing with a tripod.
So it depends a lot on your typical shooting situation.
Will you miss good shot opportunities because you don't have the right lens on the camera at the critical moment?
Will you miss good shot opportunities because you are fumbling with a tripod when you could be shooting with IS?
For me, the answer is easy.
Having zoom lets me adjust both framing and perspective to get it "just right". Having primes is a lot like having a tripod and no IS. You end up settling for something that's "close, but not ideal" in many situations.
If you don't have zoom, then when you find that perfect shooting position that gives you just the perspective you're after, you cannot frame it just right. Or if you find a shooting position that gives the framing you want, then the perspective is not perfect.
With a zoom, you can adjust both things infinitely, and get just what you really want.
And without IS, there are times when you really want to shoot under fading light, perhaps at a smaller aperture to get deep DOF, but with a tripod, you won't have time to find that "just right" shooting position before the sunset is gone. With IS, on the other hand, you could move around a lot, testing different shooting positions and different focal lengths and hopefully get things just right before the light fades, and still be able to shoot at a reasonable ISO, with a smaller aperture for good DOF, and still have things steady.
So for me, the far more useful lens setup would be the 17-55 f/2.8 IS.
Those primes are nice. And they'd be great to have in your arsenal. I can see a lot of good use for them all.
But the IS, zoom, and fairly large, constant f/2.8 of the 17-55 f/2.8 IS make it a really flexible tool in my opinion.
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Jim H.