I think the SD 1000 is definitely interesting as an addition to the BK9 in term of sounds. Some brass and sax sounds are great, I also like the piano a lot. Even if they may not be clearly better than the BK sounds, it's nice to have variations (e.g. a Ketron solo trumpet with a mild, nicely SAMPLED vibrato, not present in the BK-9 in this exact way).