The 20GB Walkman sports the same features as the 6GB NW-A1000 - this includes all of the smaller player's intelligent shuffle capabilities plus the same menu structure (for a full review of the 6GB Walkman, click here). The player can also accept MP3, WMA and ATRAC format files. The only major difference between the lower capacity player and the 20GB one is battery life. While the 6GB Walkman was rated at 20 hours, Sony says the 20GB Walkman can play up to an impressive 35 hours of music from a three hour charge. And while the 6GB version comes in four different colours, the 20GB only comes in purple or silver.