I have Isoclean fuses as the mains fuses in my CX-7eMP and K-1xe power supply. In virgin form, they provide a slight improvement in air and detail and a tad better treble extension. There are three tweaks that make a significant improvement:
1) having them Quantum Tunneled by Synergistic Research
2) painting the glass bodies with AVM
3) applying Silclear or Walker Audio SST to the gold ends
With these tweaks, the fuses make a very significant improvement in the soundstage, transparency, detail, and frequency extension in my Ayre equipment.
Good luck and Happy New Year!