The Oracle hard mat was recommended to me for my Technics SL1200G. I tried it but wasn’t really satisfied.
@stereo5 The Oracle needs to be bonded to the platter for it to do its job. You didn't do that since you were able to 'go back' (you would have had to chisel the Oracle off, since it has a pretty effective permanent sticky back) so you really didn't hear what this pad is about.