Nope. Out of those 900 discs I rented, I've only had to return maybe 2 or 3 as unplayable, and Netflix will immediately send out a replacement or the next disc

Nope. Out of those 900 discs I rented, I've only had to return maybe 2 or 3 as unplayable, and Netflix will immediately send out a replacement or the next disc in your queue, without waiting to receive the return.