Thanks for the kind words. I'd intended to post one more analysis of a specific Neumann cardioid's polar response in this thread (the KM 84 and its siblings), but my mother passed away last Sunday so I spent the week helping to close out her apartment in Pittsburgh. (Shout out to any Pittsburgh-area tapers who may be here; I'm originally from north of there.)
Now that I'm back home, I've posted a reply in the Microphones & Setup thread, "I have MK2's - Need Advice On Active Cables and a Tinybox" which discusses the practical effect of polar response in the selection of omnidirectional microphones or capsules. Maybe I should have posted it here and posted the reference there, but in this thread I was asked about cardioids, and in that thread the OP has a pair of Schoeps MK 2 capsules.
When I've rested up some more, I'll post what I was going to write about the KM 84 et al. Unlike the above two (the U 47 and the U 67/U 87, both absolute classics in the studio world and also for voiceover applications, which is another form of spot/solo miking), it's an example of a cardioid with very desirable characteristics for live stereo recording in at least moderately reverberant spaces with coincident or closely-spaced mike setups.
--best regards