Seems to me like ALOT of basses out there respond better to lower tension strings. So why is it that high-tension steel strings like Spiros became "the norm"?
Good question
Since you use guts, you certainly arent searching for an answer, but its too late for me to practice bass, and I cant sleep right now so
I will practice my English.
I guess there are some historical reasons that can answer that.
When we start looking at anything from different angles, we discover allot of pros and cons everywhere.
Metal strings initially brought a lot of pros considering gut strings, but the great majority of basses today are copies or are the real ancient basses that were built to respond to gut tension. Some of them to only 3 gut strings.
We all have to search and decide what its best for any one of us.
If we can (I cant unfortunately), we should have a proper setup made by a Luthier every time we change to a different kind of strings.
What Im about to write its only my experience, not an unquestionable truth.
These are the best qualities (for me) I remember from higher tension strings.
Faster response on right hand articulation (allot)
You can have lower action = faster left hand
Cons
At first they all sounded usable, after 3 to 4 weeks they all become too stiff, they kind of dumped the sound of my bass, I notice a decrease of volume, forcing me to play harder with my right hand trying to fell my bass responding like it did when I first put them on, but it never does.
After this I obviously have to start increasing action, and that, progressively brings a problem to my left hand.
The uneven string to string tension doesnt help either.
I always end up with a dead sound, hard playing bass that gives me no pleasure to play.
This only happen acoustically, if I always play and practice plugged to an amp probably would never had any problems with high tension strings.
But this is only my hands + my strings + my ears + my bass in search of my sound
Diferent hands + strings + ears + bass = completely different result
Always mind the setup
This becomes too long; I hope it ended useful to someone
Best Regards