@pesky_wabbit
Maybe the SME 3009 was top tier when it came out fifty or so years ago. If the SME wasn't top tier back then, which arms were? Let's not be anachronistic! It was a high quality product for its time, and priced at the upper limit of what most people were willing to spend on an arm.
What you say about the SME IV & V is really interesting. It iimplies that if one has an SME V and does not use the damping trough or the downforce gauge (or actually has them physically removed from the arm), what one ends up with is identical to a Series IV.
But one perhaps needs to remember that, as the well-known former SME dealer MIk Bhavnani says (on another forum), each SME arm is an individual hand-assembled product and no two samples sound exactly alike. The Series IV and V may now use the same grade of bearings, but does the same degree of care go into the adjustment of these bearings on a Series IV as on a Series V? Are the magnesium armtubes all of equal quality, or are the better ones (after machining in the SME factory from rough castings) selected for the Series V (as I once read somewhere)?
Maybe the ultimate SME arm would be a stripped-down Series V, with no damping-trough and no downforce gauge.