If the OP derived an improvement from trying out these Rega mains cables then he did. End of. To deny his experience and/or suggest that he was delusional may be contrary to the new spirit of this site (and probably the obj/subj cyclical argument clause of the AUP) even if his experience invokes cognitive dissonance in some quarters.
If there are any naysayers around with an insatiable urge to crap on this thread, I suggest they ask Tony's permission to resurrect an old thread entitled "Do mains cables make a difference?" or similar. There are many such threads unless Tony has binned them all.
Rega can hardly be described as Foo merchants and their mains leads are not exactly expensive so the OP is hardly risking a fortune. The consumer saviours need not therefore intervene; nothing to see here, move along.
How much are the Rega leads, btw? It would be interesting to compare them with the Mark Grant DSP 2.5s and others in the sensible price bracket.