Of course viewpoints can evolve or even change completely over time. Mine certainly have. However, I remain confused by MF's conclusion about the 12" SME arm. My point is that MF implied in this nine year old review from 2009 that the disadvantages of longer tonearms CAN BE overcome with good implementation: "a tonearm that has all of a 12" arm's theoretical advantages and none of its disadvantages." But, as was pointed out earlier, he also stated that he preferred 9" over 12" arms before he heard the SAT arm. We have this post from awsmone which further suggests that MF's review of the 12" SME arm was a clear exception to his preference for 9" arms at that time.
Perhaps this review of the 12" SME is an anomaly or outlier, and at that time MF preferred all other 9" designs over their 12" counterparts. Interestingly, MF did not comment about the sound of the 12" arm relative to the SME 9" version in that review. No direct comparison seems to have been made for the review. That would have been very helpful to support his claim in the conclusion. Absent any comments about the actual sound differences learned from a direct comparison, we are left to discuss theory. And here we are.
I have made the direct comparison. I have a clear preference for the longer arm, as does ddk for a different series of SME arms. That does not mean that everyone will have the same preference, nor that one length is inherently superior to the other. They do sound different.