As long as the disc can actually be read, the copy will be perfect. The copy can in fact end up being better than the original, if the latter originates from the end of the run of a stamper.
A pressing plant will often use their stampers for longer runs than are advisable in order to save on cost, with the result that the last CDs in every run end up being difficult or even (very rarely) impossible to read. A successfull copy, on the other hand, will always be perfectly readable.