Lots of people on youtube and online claim these big brass block make your guitar have more sustain, if this was the case, then how come all the guitar gods like Vai, Satriani, Malmsteem and many others do not use them lol
Maybe it changes the tone or even makes it worse. How come Steve who is always obsessed with tone, doesn't use any of these brass things.
Noiseless springs are pure snake oil, maybe they make a bit quieter than regular springs, but is still not as quiet as putting some tissue or foam in there
You complain on every thread, or make antagonistic claims, always with a negative connotation.
I swapped out the original trem and block on my JEM Jr with a Gotoh 1996t. The Gotoh has a brass block. It's not about it being brass it's about mass. Even an untrained ear could hear the difference in sustain. The fact you think it doesn't and the formulation of your statement highlights the fact you don't know, because you've not tried these things yourself.
As for the guitarists you mention, they all play high end, quality instruments. Some have brass blocks, some don't, but again, high end...quality which means the blocks in their trems are better still than brass (most likely) - again it's about mass. Not the metal used. High end trems made by gotoh for Ibanez fyi, using alloys etc...they know what they're doing
Instead of complaining, making suppositions and baseless claims, perhaps try it yourself. I did. It wasn't the primary reason for me swapping out the trem, but the difference in sustain was glaringly obvious.