Or do you mean the AT641? It grates the vegetables/fruits and squeezes them. The SlowJuicer crushes everything and then squeezes it. It's just the newer version. According to Kennwood, the yield is better with the SlowJuicer. I have the SlowJuicer and am satisfied.

So if you mean the Pure Juice, I would say mechanically there is no difference. One is a stand alone device and the Slow Juicer is an attachment for the Kenwood kitchen machine. But juice always comes out of the end ;o)