I'm wondering if anybody here knows anything about the Ketron SD1000, which I've seen on a few web sites including Amazon. I was looking to pick up another Ketron SD2, which I like a lot, but it doesn't seem to be available any more, at least from the places that carried it before. The SD1000 seems close in price (maybe $50 less) to the SD4, which I understand is sort of an upgraded SD2. Anybody have any experience or recommendations with either the SD4 or the SD1000?