@yyzsantabarbara - Regarding using a PC vs. hardware RCS. Devices like the Anthem and Wavelet use more powerful computers for generating filters, which is the computationally intensive part -- I suspect it involves numerical optimization. Convolution in playback is handled by specialized hardware (DSP chips) in the preamps. I have no way of comparing such DSP hardware to a PC (better, worse, more efficient, whatever), but by using the external computer to make the filters, it seems they have sidestepped many of the issues with dedicated hardware.
Of course, with time, correction techniques will develop and may need more powerful playback DSP; but in time, everything becomes obsolete, anyway. IMO the simplicity of the Anthem or Wavelet paradigm is a reasonable tradeoff for many people. (I don’t like having a PC in my music room, though I understand that many users use them with great pleasure and success.) More than one way to do things, it seems to me.