The WK1630 76 key Casio keyboard is very good for it's price point. Yamaha also makes their PSRGX76 keyboard which is the same price. The advantage of the Casio is the ability to make your own styles from scratch and the ability to create your own sounds using the internal synth editing. The piano sound on the Casio is very realistic but some of the other instrumental sounds such as trumpet, Sax are better on the Yamaha.
However, bang for the buck, the Casio has a slight edge in my opinion. I sell both of these products in my store so I am familiar with both really well.
George Kaye
Kaye's Music Scene
Reseda, California
818-881-5566