It is tough to give you a good answer without knowing your sound system... obviously certain systems will sound cleaner out of box than others, regardless of input... that being said, optical is fully digital, and provides slightly cleaner sound... it is kind of like comparing CDs (digital) to cassettes (analog), although the discrepancy is not as huge... for example the S/N ratio is quite higher in optical than in component (or any analog for that matter), this is in part due to the fact that optical signals are not going to be affected by electromagnetism in the vicinity, while any charge carrying wires (component) will be affected by magnetic fields. There are numerous other reasons for optical being superior, but the difference can be tough to hear, especially out of poorer sound systems