My own experience of these things;
Bought a RA "Silencer Block" some 5 or 6 years back for about £340 including mains lead and was satisfied it made a beneficial difference in my system. (LP12/AAA5/Avondaled Naim 32.5/Avoldale APX2/Avondale 260Z/Castle Howards)
Corresponded with Roy K Riches via PinkFish a few years back who provided to me his papers on Hi-Fi mains. I also acquired a couple of his "Beast" mains leads for a reasonable sum and was again satisfied that there was a beneficial difference in my system.
I have in the last couple of months built a DIY 6-way hydra based on RKR's guidance to replace the RA mains block. Cost about £30 since I have retained all the same mains leads but £20 of this was a new E-Bay sourced Wattgate plug since I had cut one of the "Beasts" in two. I was blown away by the significant improvement in my system, should have ditched the RA mains block ages ago! Mains leads remain a mixture of RA and RKR "Beasts" but hardwired to the hydra, removes a few fuses from the equation.
I sold the RA mains block on E-Bay for £150 and received a message from the very satisfied buyer who was delighted with the improvement it made in the sound of his Arcam System!
You pays your money you take your choice as they say!
excellent stuff.