A major reason you are seeing a product like the WK7500 is do to Casio USA have been hiring former Yamaha people who were product and marketing managers in the arranger and digital piano divisions. I personally know one of them very well and I was thrilled to see him show up at Casio. It brings a wealth of knowledge to Casio's arranger division.

You can record in both the 17 track sequencer and the pattern sequencer in both real time and step time. A pattern can be up to I believe 32 measures ( or maybe just 16). I'm not at my store now to look at the owners manual.