I am always amazed when people question whether they are entitled to a replacement. It's simple, if the phone has a defect you are entitled to a replacement. You did not walk in that store and enter into an agreement with Apple to purchase the phone for $299 (or $199) with certain defects being acceptable. You walked in there, paid full price, and should have a product that you are pleased with.
Put it this way, did you walk in and say "today I am paying $249, I will accept light leak and plastic overhang in exchange". Of course you didn't, so if they won't accept a compromised price from you, you should not accept a compromised product from them.
I am always amazed at what junk people are willing to accept from Apple, I am not one of those people.