I have two Refurbished MM's; (Late 2012), 2.5 GHZ, 16GB RAM, 500GB HD and the other MM(Late 2014), 2.8GHz,8GB Ram, 256 SSD. The MM(2014) is a speed demon in starting-up and opening Apps. However, I have recently "burned" over two Hundred(200) DVD's from my extensive DVD Collection using a software titled MAC DVD Ripper Pro and I saw no significant difference in the "Burn" speed. So, it appears that "burn" speed is almost the same on a HD or SSD?? Also, I am using a Apple Superdrive to do the "burning". By the way "Mac DVD Ripper Pro" is a excellent product.