The main benefits are smaller, lighter and firmer breasts. They will be in proportion to the rest of your body. This also means no more physical discomfort such as a backache or neck ache. The areola (the brown circular area around the nipple) will be smaller and better proportioned as well.
The scars will fade but breast reduction surgery does mean extensive scars which, whilst they fade, will be permanent. They will fade to thin white lines.