Martin,
I was on your homepage before, a very good overview.
I have three Mini Whip versions: PA0RDT, PA0NHC and PA3FWM.
I use them in an urban situation.
Testing them in the upper VLF band (20..30 kHz) with the same Bias-Tee and in the exact identical position, the PA3FWM version performs best (signal quality, SNR), directly followed by the PA0NHC.
But I think this is perhaps a bit off topic in this thread.
Dirk