Having been in an Apple store on more than one ocassion I can promise you these imperfections are done on purpose. Geniuses are likely given confidentially handbooks describing where to locate these defects so they can deny legitimate warranty claims by saying you physically damaged your mac.
If you plan to exchange it than you have until January 7th, but expect a replacement coming mid-January or by the end of January. I requested a replacement the initial day (12/17) I received it for cosmetic marks and I was told January is when the new one will arrive. You might have to wait 2-3 weeks from the day you return it before your new one arrives. So if you can go without the machine in a few weeks than by no means go right ahead and replace, I personally would if it's in front.
Apple rep and I have it documented told me I could keep current iMac that's got a couple of marks until new one arrives. He said to it ignore the 14 day USPS mailing label.
When I get replacement iMac than I could ship iMac with marks back to apple.
No way would I wait another 4-5 weeks for another iMac.
I don't understand this indifference when it comes to products YOU pay for with YOUR money.....What about when it comes time to sell it for a new machine? Guess what, that imperfection will drastically lower its value because the person buying it will not care whether you caused it or whether it came like that from the factory. They will expect a lower price, that's how it works. Apple will do an advance exchange which means you keep the machine until the new one arrives so there is little you have to do except make a bloody phone call. Don't just sit back and accept crap, you have to be a little ore proactive in your lives. Some of you frighten me with your ridiculous complacency, no wonder the world is the way it is.
I have the tiniest imperfection on my iPad 3 that I didn't notice until several months after I bought the device. It's a tiny little nick near the 30-pin connector. No one would notice it unless I pointed it out and other than that the device is flawless and works perfectly. I'm sorry but I don't think I'm accepting crap by not exchanging it for a different device. But I'm sure if I posted a zoomed in photo here I'd have plenty of people here telling me its unacceptable and I should've gotten it replaced.
I noticed a 4 inch scratch on the glass of my 27" 2 days after I got it. Apple is sending me a replacement... I get to keep my current one until the new one gets here.
Can't really see it during normal use, but it bothers me to no end that it is scratched and I'm not the one who scratched it.
If it's on the black frame it could be glue, mine came with a few hairlines that disappeared after cleaning it.