Having more is better. Not only does it mean that copying cd's and dvd's is easier, as it can be done directly (also known as 'on-the-fly', but it also means that you can use both at the same time. Say you always play a favourite game that requires the disc whilst playing, you could have the disc inserted into the drive, yet still use the other one for doing your every day-to-day stuff that requires the use of a media reader