I sure know where you are coming from. I am waiting for my Nikkor 24-70 to come back from repair from Nikon. Teh Nikkor and Canon 24-70 are very similar lenses, and cost near the same price. In my case I dropped the lens alone, not the lens and body. Two feet to pavement. It appeared to have no damage, but afterwards while it would auto focus fine, all images I shot were all soft at the edges. tried it on two camera bodies, same thing.
So back to Nikon, and the repair cost is about 1/3rd the price of a new lens, but what can you do? 7 -10 "businenss days, if the parts are in stock" before I gt my lens back. Grrrr.
so two bits of advice. Not wanting to scare you, but with a lens that good, you maybe should look real seriously at sending it back. now in my case, the apparent loss of image quality was visibile right away. but why take chances with such a good lens.
Another thought is your next purchase, if any, look at some of those Zeiss manual focus lenses. I use them myself. The reason i say that is in the past I have dropped manual focus Nikkor lenses, and they still work fine and are very sharp. Not that I want to put the issue to the test with my Zeiss, but one thing all those lens tests and lens reviews never seem to cover - at least none I have seen, but do correct me if I am wrong - is with all these new auto-focus lenses, especially zooms, and double especially if they are image stabilized / vibration reduced is, you ever drop one, more often than not you are toast. That's from direct experience. The Nikkor 24-70 is one of their best "professional" lenses on the market today, and a two foot fall did it in. My older Nikkors, bigger falls (one, once down a cliff), and they still work fine)
so something to think about. Good luck, and get that lens looked after asap if you can.