Is impedence so important for a pick/phono combo?

Today I'm living up to my moniker Bombaywalla 'cuz I'm writing from Bombay, India! Am visiting the home I grew up in & where my parents still live!

As TWL mentioned above, it is important to get the impedance match betwn cart & phono pre correct otherwise one can severely degrade the sonics of the cart. Electrically speaking, the phono pre impedance should be 10X that of the cart. so that it doesn't load down the voltage coming of the cart. I think that you have this already but, I agree, that not everyone agrees as to what the correct value is over & above the 10:1 general rule-of-thumb as everyone's ears are trained different.
The capacitance in the phono pre + that of the cable & the the internal DC resistance of the cart. forms a low pass filter. Wrong selection of the phono pre input impedance can cause this filter to attenuate freq. in the audio band & give you vastly degraded sound.
There is a good dissertation on this on the Hagerman Technology website or on the AudioAsylum FAQ page (in the vinyl subsection). It clearly states the advantages of selecting the correct impedance. It is shown graphically as well & it worth your time to read it.
FWIW.

Just another voice to say, "Yes, it is important".

We recently tested some very small load changes with our Shelter 901. Most people with this cartridge prefer a load of about 40 ohms (running through a stepup). We tried multiple values between 30 and 50 and had no difficulty hearing the differences between each of them. Load changes as small as 1-2 ohms were audible once we knew what to listen for. You don't have to go to that extent, but you don't want to be wildly off the sweet spot either.

Rwd, LOL from your story of Lyra's "specification" for the Helikon. 100 to 47K?! My guess is they're just pretending to mate well with every phono stage on the planet in order to sell more cartridges. As you heard, the improvement when you load the cartridge properly is significant.

Hey Doug....you're right! I also checked the Benz M specification I had and it was something similar!!

Rick,
Have you tried to load the input of your ARC PH3se down to 500ohm? It may give you the same body and warm as the Rhea.

Is there a way to know exactly the optimal load impedence of a cartridge?
Thx
Zender