People who work with Karaoke/CD+G discs care a great deal about the audio/visual quality of the discs. Because the CD+G format is a difficult format to copy, you need to ensure that the duplicator you use have 2 key elements:
1) A powerful CD+G capable controller able to operate the duplicator and control the drive(s) to provide the highest quality capable.

2) An effective hard drive to read the audio and graphics to the writer accurately with high quality to eliminate glitches and prevent the screen from jumping. Only if those 2 features work effectively with each other will you truly get a 100% exact duplication from the original material for CD+G duplications.