Linear tracking tonearms.....

Check out the Schroder LT. It's a pivoted linear tracker.

Hiho, I forgot about the Cantus. Not bad looking. That glass tube looks like it has the potential to resonate allot. Especially since it is cantilevered out of the base, with no support on the other end. Some of the air bearing arms look like they have the same possible design issue.

Peter, Most linear tracking arms I've seen have slotted head shells. So they can be adjusted to compensate mis-alignment by other adjustments, like VTA, and VTF. Most have a protractor with a straight line (instead of an arc), with lines that are 90 degrees off the main line to line up the cantilever (zenith).

One exception is the Thales Simplicity. With the design of the Simplicity you would have to take the head shell off, to align it, in it's jig. This is not ideal because you can not align the stylus with a load on the suspension. Since we know that different VTF will change the alignment (overhang), there is no way to know for sure if it's perfect or not.

As said above, if the alignment is off on a linear tracker the zenith will be off a little all the way across the record. Not sure how audible that is but I will look at Dgarretson's link about that.

Hiho, that's true. You still have to take the head shell off to make an adjustment, because you can't get to the cartridge screws with it on the arm. That's allot more awkward, and will take much more time to dial in.