Interconnects - better before preamp or after preamp?

There is no 'better' cable. Cables interact with the connected devices. The 'best' cable is the one that provides the listener with the most satisfying sound with the equipment they own.

I flat out guarantee that most AudioPhools who purchased cables by brand or other people's opinions have sub optimal sound.

Very good points herein.

I think why everybody gets so excited it's because they hear differences between cables.  And sometimes the differences improve the experience.

But lots of cables with all those twisted strands that are creatively shielded inside a cable Color the sound.

Coloring the sound and making it sound different is what audio quest, cardas and especially Shunyata do to the sonic signal.  I think it's really deceptive as hell that High end audio Cable manufacturers do this.  You buy it it sounds different and you are impressed, all this for several thousands of dollars. It's a scam. Coloring cables is a scam. 
 

Producing a neutral Cable is what should be pursued if you want the Signal to not be impacted by the cable.  Very tough to figure out who these companies are that do this.

Buy pro cable (hosa, mogami, roland etc..), it’s why I don’t worry about it.

There is no guarantee that any particular cable brand or style works best with any particular component. Add in the listeners' sonic preferences and all bets are off.

I've had 'critical' listeners with expensive HiFi systems tell me that my system has 'no bottom' and and another 'no sparkle' while those who know live music make comments like "Joe Pass is sitting right  T H E R E !!"

It's time correct with a slight downward drop from ≈25Hz to >22kHz - ala concert halls.