Linear tracking turntables, whatever happened?


Curious as to the demise and downfall of the seemingly short lived linear tracking TT.
Just from a geometry point of view I would have thought a linear arm should be superior to one with a fixed pivot that sweeps through an arc.
Obviously there is much more to it than that, sort of the reason for this thread.
I am genuinely interested in trying one out for myself as well.
128x128uberwaltz
An interesting story [possibly apocryphal] about Jack Rabinow, the inventor of the Rabco Linear Tracking Tonearm : While traveling on a train, Jack went to use the restroom and was intrigued by the sign, "Please Do Not Flush While in Station",  and when he returned to his seat he began figuring out a way to disable the flushing function of the toilet when the train was standing still.  He took some wire coat hangers and twisted them into a device that did exactly that !  I guess that kind of thinking was the same that went into the original Rabco tonearm !  I owned one for a few years and even tweaked it with a balsa wood replacement tonearm but never was happy with its clunky performance.  A Revox b795 and a Technics SL-10 were next in line and both were good TTs, but it wasn't until I mated a Souther Linear Tracker to my Garrard 301 TT that I finally realized my "Audio Nirvana". A Lyra "Helikon" cartridge is supremely happy with the arrangement. On very rare occasion the "tonearm/trolley" that holds the cartridge and runs along two parallel quartz rods will hang up and require the rods to be swabbed with alcohol to correct the problem.  I see no other TTs in my future --------- .
@bdp24 ,

The ET was on a VPI, will be on my TT project at some point. I'm using a Funk Firm FXR on the Rock 7 The FF arm has X bracing in the arm tube, making it very stiff. Has Max ever released his latest arm?
This has been a pretty informative thread~
For another story, I knew a guy back in Pittsburgh, where I grew up, who mounted a Vestigal arm (remember those, with the wagging headshell attached to a string which tensioned it?) to a Rabco. In theory, I guess it made sense.* In practice, I don’t remember. This was back in the mid-’70s.
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*Or maybe not, given the discussion of vertical inertia here- I don't have the physics knowledge to assess this meaningfully. 
Please tell us what Rabinow did with coat hangers to prevent a toilet from being flushed while the train was in the station. Inquiring minds want to know.
@bdp24 ,

I failed to mention that I have a Moerch DP8 that I'm planning on using with the Rock 7 at some point as well.