Dear Downunder: Well, it seems that the only one that changed from 12" to 9" was me and let me tell you that I change six long tonearms for the short ones because I can't find a real/true quality sound improvement in the long ones, maybe my music/sound appreciation and music/sound priorities are totally different from yours, that's all.
+++++ " Me I have had two 12 inch arms for a few years now so I can appreciate the better tracking at the end of a record compared to my 9inch naim ARO arm.... "+++++
IMHO this kind of performance/behavior is almost totally dependent on the tonearm/cartridge combination and not because one tonearm is longer than the other one. Here we have to remember that the Aro is a unipivot design that are not the best trackers at inner record tracks. For you can get to your conclusion you need a 9" Aro against a 12" Aro and even here the result is dependent with the cartridge match with either tonearm model.
I had that experience with the Audiocraft AC-3300/4400 and the Morch DP-6 where the only variable were the arm wands size and there is no differences that I can say: " it is because the arm wand size ".
As I already posted in a well tonearm design and well tonearm execution ( build ) the arm wand size can't make " the differences " for the better in a 12" against a 9-10" one, there are other factors that are more important and critical for the quality sound performance and I'm not saying that the size is not important it is but not at the level you or other reports about but because of its disadvantages against it " theoretical " advantage.
It is the same for ( IMHO ) the false assumption about the " perfect/mimic " cero tracking error advantage of the linear tracking tonearms, there are a lot of other factors that have a huge influence in the whole tonearm performance. Of course that some people like the linear tracking or long pivot tonearms but that does not means that are better ones and for the reviewers that support those tonearms designs we have to think/take in count that they have/must support to their advertisers and to the today products: specially the " new kid in the block ", very difficult to really trust on them: they are part of the audio business, I can and understand that.
IMHO you can/could obtain almost perfect/stellar/excelent quality sound reproduction from either tonearm design: long or short one, obviously with the right cartridge in either tonearm design and I can tell you more: either of these ( well cartridge matched ) pivoted tonearms outperforms ( overall ) a well matched linear tracking one.
Regards and enjoy the music.
Raul.
