I have heard people saying they tried something like this, but they were told that Apple would send them a shipping "thing" they would have to post the iPad back to Apple who would take a look at it, and then if deemed faulty, they would then ship a replacement back to the person.
In other words a long time and risks in doing it this way.
I fully understand what you mean about going back to others stores as these are just general sales people who are not trained by Apple to know how to treat Apple customers expectations. So it's totally pot luck if you get a person who agree's with you, or just thinks you are being overly fussy.
Luckily if I was in such a situation, I still have my iPad1 so I could take them somewhere out of direct store lighting and demonstrate the iPad1 did not have the issues.
I'm sure otherwise you might get into an argument with a sales person who was trying to tell you it's normal and they are all like that.