I feel these I.R.A, PLEK and aging treatments may not necessarily sound "better" but give the bass that worn or played feel (a bit of given for ageing)
Yes, a new bass feels and plays nicely - but I've found a bass feels better the longer you keep it and get used to it. This processes take the shiny new age off it and make it feel a bit more broken in.
As with everything, some like it, some don't and some don't notice.