Congrats on your new keyboard. I too own a Casio WK-3500. It is an awsome keyboard, and Casio deserves a pat on the back for this model. They did an excellent job with the sounds, and even added features that I wouldn't expect to see on this type of keyboard. I'm still amazed that the Casio WK3000 and WK3500 will allow you to load new samples into the board. The sample memory is a bit limited, but geez what a great feature to have. Plus the drawbars, and smart media storage was a very nice addition. The only downside I find is that they dropped the ability record user styles.
GEAR: Yamaha MOXF-6, Casio MZX-500, Roland Juno-Di, M-Audio Venom, Roland RS-70, Yamaha PSR S700, M-Audio Axiom Pro-61 (Midi Controller). SOFTWARE: Mixcraft-7, PowerTracks Pro Audio 2013, Beat Thang Virtual, Dimension Le.