The improved loading speed is very beneficial when it comes to creating new characters.
Since you have a US serial, you don't need to use your GD-ROM at all; the CD will accept your serials when you go online for the first time. For people with JP and EU serials, you can create a new character using my disc to get the fast loading, then switch to a GD-ROM to enter your serials the first time you go online with the character you just created, then switch back to my disc again after you've been online once.