I wondered about whether something else, like the torque on the mounting screws, had also changed. I have my doubts about whether a small improvement in overhang would result in a big change in sound. Also a change in overhang would make the sound better for certain parts of the record and worse for others rather than provide a uniformly superior sound.
As for the advantages of linear tracking arms, there are MANY theoretical pros and cons. Some tone arm makers think that most linear tracking arms are actually worse at maintaining perfect tangency. That is because as the stylus/cantilever move inward the arm resists moving more than would a pivoted arm. The arm resists moving laterally more than conventional arms because they tend to have high mass in that plane of movement and because of the loss of the mechanical advantage of a pivot (it is easy to move something around a pivot, much harder to move the entire arm laterally along the air bearing tube, even if friction is minimal). This resistance means that the cantilever is more inclined to being forced out of position (bending inward) with linear arms. Obviously, the short arms on linear trackers can be made very rigid and less prone to ringing, but, there are arguments as to whether the lack of a conventional pivot prevents vibrational energy from being drained away and dissipated properly. I don't know if these theoretical claims are true or not; I've heard nice reproduction from linear arms as well as conventional arms and cannot attribute differences to particular design elements. To me, having noticed how small VTA changes affect sound, I am also concerned that the short arms on most linear trackers would result in larger shifts in VTA for different record thickness than is the case with a longer arm.
There are pivoting arms that take advantage of the "Thales" circle geometry to maintain tangency (also no skating), but, these are expensive, complex, and most require additional arm pivots and parts (added friction). Some examples are the Thales arm, Schoeder LT, Funk Firm AK-1, and the Reed 5P (the Reed avoids extra pivots that the stylus/cantilever must move by using a motor controlled by a light sensor to pivot the tonearm base to maintain the tangential geometry).
