This is very interesting.
I'm going to suggest that the Furutech is not universal in all applications. I purchased several for an NAD integrated. Now, keep in mind that an NAD has a rather "rich" sound, weighted as it is towards the midrange and bass.
With the Furutech, I noticed a "leanness" to the sound that I did not initially notice (I have Furutech outlets as well and thought them very good), but eventually decided to test out my theory by buying a pair of 6.3 amp Synergistic Research fuses for the NAD and replaced the Furutechs. The other two fuses (there are a total of 5 fuses in the NAD) are still Furutechs.
I was chagrined to realize that the Synergistic Research restored the tonal color of brass, and that the "bleached out" sound I had heard was immediately attributable to the Furutechs. I am speaking of their placement in the NAD so far.
I also had a Furutech in the PS Audio Power Plant, so after putting the Synergistics in the NAD and immediately realizing that the sound had gone from that of Premium Ice Cream to that of Ice Milk (thinner tasting) with the Furutechs, switched back to the Synergistic fuses I had previously had in the PS Audio (I have both the SR and the Red in 5 amp size, which fit the PS Audio) Power Plant. The same effect occurred: tonality was restored - and not a euphonic tonality. I know this because I love brass instruments and hear them live frequently enough to know their sound. Perhaps it is merely the place one puts the Furutechs, but I could "see" other instruments, such as flutes, piccolos, and clarinets being restored - tonally speaking, to their original tones. I could see if it only happened on a few CDs, but the Mercury Living Presence CD of Tchaikovsky's Nutcracker is one of Mercury's best CDs, and it is NOT lean. I've heard it with Jadis equipment, VTL, Antique Sound Lab, Hegel, Parasound and Conrad Johnson over the past 25 years (it is one of my favorite pieces of music) and it has never, EVER sounded bleached out. At least, not until I put in the Furutechs. Soooo, I would recommend that one proceed with caution.
I saw another thread where the poster also noticed a "leaning out" of the mid bass. I would suggest the Furutech might also lean out the upper bass fundamentals, too. This is not to disparage them, but they are the only ones (out of Hi Fi Supreme, Synergistic and one other expensive fuse whose name escapes me right now) that has produced this effect. I had even put Furutech IECs in my Hurricane amps, and wondered why they did not sound quite the same. I'll have to change to another brand of IECs before I can be sure (one amp at a time, so I can maintain control of the experiment), but the sound is still harsher on the brass on the Mercury than it has ever been. I will be getting a Synergistic fuse to place back into the NAD (the third of 5 fuses), a 500mA fuse. That should tell me what I want to know.
Again, not at all a condemnation. Just a caution.