In the real world, I know that comparisons can be difficult but possible. In my opinion, with all other elements being equal in the audio chain for comparison purposes, it is the cartridge that makes the biggest sonic signature combined with the turntable and arm components resolving abilities.
Let me amend that statement by saying that it is relative to the quality of both units being tested. I feel that the Rockport and Walker are of equal quality in terms of construction and designed philosophy to say this.
Everything in this hobby has an audio signature no matter how good or bad it measures. There are degrees of course, and I feel that good measurement is fundamental to accuracy of recorded material but, as we all know, nothing is absolute. I know that if a cheap $80 Shure were on table 1 and a Benz LP (one of the finest I have ever heard) were on table 2; it really would not be fair, although I am convinced that both of these tables would exhibit, like the best gear, some recognizable information retrieval impressions despite it. To my ear, my decision making would have to be predicated on both cartridges being equal.
Thank you all.
D.H.