The Sony CDP-CX455 400 disc MegaStorage CD changer is an upgrade to the pre-existing CDP-CX-400. However, if it is an upgrade or not, that is left up to user preference. The CDP-CX455 can store up to 400 discs and has the capability to playback audio, CD-R, CD-RW, and MP3 CDs. The changer features two jog dials for easy CD access and dual LCD screens that display current and next CD information. Users can take advantage of the CD-text reading feature, or manually enter CD data using a PS2 keyboard. Additional features include the ability to connect to another unit for 800-CD capacity and the ability to program the unit to play songs in various orders. Connectivity options include an analog RCA output, digital optical output, analog connection for synching units, a Control A-1II connection, and a headphone jack. Though the CDP-CX455 has many features, certain drawbacks question if it is really an upgrade to previous models. The changer comes with a cluttered remote that is not very user intuitive. Also the player does not have fast forward or rewind buttons, only skip buttons. Users do not have as many options in classifying CDs as the player lacks the "group" option found in the older CDP-CX-400. Also the player has a 20-character limit for artist and album name, which is hardly enough space for some album information, let alone genre. Manually entered information is assigned to the CD slot, so if you put in a new CD, it will retain the old information. Last but not least, the player takes a painstakingly long time to change between discs. Overall the only major feature that the CDP-CX455 has over its predecessor is the ability to play MP3 CDs. Serious audiophiles should think twice before purchasing this model, as it is a mixed bag when it comes to features and flaws.