Atma-sphere MA-1 MK 3.3 - Fuse Replacement Vs. Upgrading Power Cord

This keeps troubling me. I am about to replace all the standard fuses with SR Blue. I read that many have tested this SR Blue and very happy. There a total of 6 fuses, 3 on each amp.

I was wondering, would the improvement more significant between replacing the fuse or upgrading the power cord. I am using AZ Absolute right now for both amps.

Has anyone replaced the B+, Filament, or the circuit fuses of MA-1? What is your experience? Is it significantly better? Thanks!