Apple will be revising their iPhone warranty and return policy in South Korea due to customers that were unhappy about their current return policy. If a customer receives a defective device they will be able to exchange it for a brand new device instead of a refurbished one within 1 month of the original purchase date.

Korean iPhone customers are not happy about Apple replacing defective devices with refurbished ones that have used parts in them when the actual warranty states they are entitled to a refund, new device, or free repair. When Apple spokesperson Steve Park was asked about the new warranty policy in South Korea he declined to comment.

I've personally never had any issues with refurbished iPhones from Apple. I've actually had better luck with them than brand new out of the box units. I've actually heard that refurbished units undergo a more rigorous testing cycle than brand new units. Not sure how much truth there is to that but I seldom have issues.

When Apple exchanges your products are you ok with receiving refurbished units? Have you had issues with them?

Bloomberg