Upgrading Fuses

Just upgraded the fuse in my integrated amp. Didn't change the world, but did make a positive difference. Well worth the $40 spent.

They work, but it will depend on the resolution of your system to determine just how big an improvement you'll experience. Expect to be disappointed for the first few days as they, like anything, need some time to break in. I kept my system on for 4 straight days at a very low setting and from time to time would check in on it.
It went from 'what the hell is going on here' to 'that's very nice indeed'.

"All advice appreciated."
I think they are selling mass production fuses with gold(ish) plating on the ends & some fancy decals and packaging.
That said, if you can just buy one fairly cheap & see if you think it makes a difference, what the heck.

I think they are selling mass production fuses...

Maybe with some makes but the HiFi Tuning fuses I use are made of ceramic instead of glass, to control resonance, use silver wire, and are cryo'd. It's not snake oil.
There are enough reviews out there from 6moons, PFO, Stereophile, and Stereo Times, to name a few, that think very highly of them, not to mention enough testimonials from us average Joes (and Janes) to start a blog.
Check out the other threads on this and go with a reputable make and you won't go wrong.