Yeah, they are nice indeed. I have a M367 here right now. It's my understanding that it's the same mic with a different connector.
I had the opposite problem though, as the voltage was 160V, and the headroom just went to shit as a result. When I fixed that, the sound got so much better. I'm going to replace the PSU with one of Oli's though, to protect the tube. Have you measured the voltage when you power up the mic, to see if the Korby ramps the voltage or just goes full on? The PSU I have here jolts it, which is the main reason I'm making the change. I just spent a the same amount a pair of AC701s that we used to spend on a single VF14.