I don't know if this got mentioned in the discussion but I came across a living and breathing (ie in a store) Bob van Asperen WTC1 on the (real) christian zell hamburg 1728.
Bobs playing is as always like double cream and the Zell just is, in the most Hindu sense: neither good nor bad, bending to the will and voice of the music.
A big late Italian would be a splendid choice for Bach as well.
Anyway, critical specs are Virgin veritas 0946 3 49963 2 7
Doug.