I have a Buffet Expression Series Alto sax, which is from what I understand was made by Keilwerth and was the basis for the SX-90 Series. I love the big full rich sound of the horn. I have an opportunity to purchase a H. Couf Superba II alto in excellent condition for a very good price, but I need to drive a few hours to go see it and test play it. My question is since both were made by Keilwerth, am I going to notice any real difference in tone characteristics of the horns or will I be buying a horn with very similar tonal qualities? I really don't need two horns that will sound similar similar, but the Couf is at a price where it is very tempting. Any guidance, help, etc would be appreciated. Thanks!