Bad Nady
You are right about the unmodified Nady TCM-1050 clip. The performance is distracting, and the strings were different and old. The other clips were made within a few minutes of each other.
Marik and I recorded clips over a period of a couple weeks just for mic testing purposes, so we didn't try extra hard to make the tests scientifically replicable. We did try harder later on in the process, but there's only so much you can do to standardize this sort of test.
I learned a lot in the process of testing and revising micophones, and I'd like to start a new thread on what I experienced, and what sorts of things Marik changed. I'll try to get that up soon.
I would actually choose the very modified Nady if I could only have one of the large diaphragm, small diaphragm, and ribbon mic's that we tried. It sounds really nicely detailed in the highs and mids, and has nice bass, too, while the K87 capsule'd tube mic sounded a little too smooth or flat, and lacking a tiny bit in transparency or detail. Other people might certainly choose differently.
The original Nady has a kind of fuzz all over the bass that made it thick and overbearing sometimes, and kind of aggresive and ugly highs, and not much good going on in between.
These kinds of things are more informative live than over the internet, but still worth a listen.