My Rent the Runway experience was fantastic! The dresses arrived Thursday afternoon, so even if I had had a problem there was plenty of time to run to the mall for a replacement.
The dresses arrived in a garment bag. One in my regular dress size and the other one a size bigger. I tried my regular size on and it was a perfect fit! You can see the pictures from the "black tie" wedding. I certainly was pleased when several people commented that I was wearing their favorite dress of the wedding!
Returning the dresses was simple too. They provide you with the return label. You slip the return label in its slot, zip up the garment bag, and drop it off!