Shane, sound quality wasn't discussed as a factor since with any well-designed modern player audibly flawless CD reproduction is a given. We've all read how for some mysterious reason a "dedicated" CD player is better than a CD/DVD player, but there's no factual basis for that these days. CD/DVD players use dual lasers, 650nm wavelength for CDs and 780nm for DVDs/SACDs, each being the optimum for reading those discs.
As far as the number of discs go, you're certainly right to want more convenience, and a megachanger maximizes the convenience factor. With a carousel, picking out a new disc and manually inserting it is still required if it doesn't happen to be one of the few already in the player. Your entire collection could be permanently stored in a megachanger and could be either simply catalogued with a written list or entered into the player memory with a rather tedious process.
