First thing to know is what weight shaft you really are wanting. The KBS is 57g and the Xcal appear to be 75g range. That’s quite a difference. If you are looking at going to a lighter graphite, like the KBS MAX 55 but want a less expensive option, then Fujikura Vista Pro 50 R2 seems to have a similar profile to the Max 55. The R is slightly firmer. If weight doesn’t matter and you are OK trying something up to 75g, then I like our Pro Series in the A or R flex. They are a little heavier and slightly firmer in the A and R flex than the Max 55, which is an A flex. You club head speed indicates you can play an R flex, but if you have a slower, smooth tempo, an A flex might work as well. The Tensei AV Silver is a new option we have and in the R flex you would be 74.5 grams and has a relatively similar profile to the KBS MAX, but at a similar weight to the Xcal. That might be a good option to try.
Just going to have to do some experimentation. Even with similar profiles, you never know for sure until you try them. I would tend to lean toward the Vista Pro, which has multiple weight options to consider, and the Tensei AV Silver if the mid 70 gram weight is what you decide you want since the Xcal work well for you.
Britt Lindsey