@ivanj , I have 645-8s. They were a custom job as I could not tolerate the width of the standard 845. I am definitely in agreement with most of what you are saying. Turntable isolation is critical. However, wall shelves can be a detriment under certain circumstances. It is not like walls do not vibrate. They can vibrate more than an appropriate built in on a concrete floor.
Yes, phono cartridges are inherently balanced devices. But, I would never put a long cable on a tonearm. I would put it on the Phonostage. Many now have balanced outputs.
Absent the ability to put the turntable in another room there are other ways to lower sound pressure levels around the turntable and cartridge. Using a suspended turntable under a dust cover is one solution. Mark Dohmann told me that he is working on such a solution for the Helix.
I have listened to Peter's Strain Gauge on his system and I was duly impressed. The only stick in the mud is it's tracking ability. I never heard it misstrack but the measured data is not complimentary. If you do not tend to play difficult records it is not a problem you would notice.
Merry Christmas to all,
Mike