Transparent users... Question

I may be upgrading cable soon, actually I know I am upgrading the speaker wire to Ultra (w/MM) but my interconnect between pre and amp (LS15 and Proceed hpa2) is currently balanced Ultra (w/XL. Would it be worth it to go for Ref single ended or shoot for the Ultra MM balanced? Thanks for any advice.

I will say that after wiring everything with Ultra MM the change was nothing short of amazing.