Old topic, but hey!
I've just received a Midtown neck pickup to upgrade my Rivoli bass. "Upgrade" may be too strong a word, but I was finding the Artec sidewinder was just too hot and restricted, tonally, to be much fun.
The Midtown pickup is strange. Mine isn't microphonic until the cover is installed. At a guess the cover is made of ferrous metal. If I hold the cover over the pickup, without touching any part of the pickup directly, the pickup will reproduce any light taps or knocks on the cover. Install the cover on the pickup and it will reproduce every tap and knock very clearly. I'm figuring out a way of padding the pickup slightly to isolate it, mechanically, from the cover. A plastic cover would be even better.
Remove the cover and tap the pickup itself and there is no noise. The coils seem well embedded in clear epoxy. Overall the pickup is well made, with a chunky brass backplate.