I'll talk
as if I truly understand...The Linkwitz mod changes the internal FET configuration to source-follower mode, enhancing linearity and max SPL of the capsule.
Translated: if you play around with the wiring, the capsule sounds better and doesn't overload as easily.
The cost: your time, probably a couple of capsule casualties as your learn, and the sensitivity (output level) is lowered, which could be a good thing if your preamp is easily overloaded (Sony DAT pres)
To the best of my knowledge, this is what a standard CSB is (not low cost, not HEB) - Linkwitz mod'd WM60 (maybe a 61)
http://www.linkwitzlab.com/sys_test.htm#Mic - scroll down to 'microphone'