Great post Suporator! So many of us have been lucky to follow parallel journeys. Our wallets have suffered but I would sure do it all over again.

I think it has more to do with the wave you're trying to ride, rather than personal preference.

My local is a dumpy beach break, mostly mushy but sometimes very slow rollers that break very fast on a shallow sandbar.

In these conditions longer boards generally suck, just because they're too unwieldy to turn when the wave picks up speed and you need to get down the line ASAP before you die. A shorter (but not necessarily wider) board is amazing because you can line up closer to the break, drop straight onto the face after a single stroke or two, turn and get down the line.

When there's actually a nice swell that rolls and you can hit a bigger (and cleaner) outside break, the long narrow board is a lot more fun because you just have so much more wave to use, and the swell is slow enough that the speed of the longer board helps a lot.

My main board was a 7'8 x 29.5 and felt it was perfect. If I lived somewhere else it would probably be different, though.

There are so many variables that come into play.
But from a performance level point of view there,s 2 ways to look at it.

A performance surf sup, is designed to be surfed off the tail. Much like a shortboard.
If your ideal volume is 130L that means you're gonna be around a 9"0-9"5 (27"-28.5 wide) board.
But on the other hand, if 90% of the time, you're surfing 1-2ft waves, then a 9"0ft plus board will almost always stall when surfed off the tail.
Enter shorter and wider.
In a compact style shape a 130L board could be somewhere closer to 8"0-8"5 long (30"- 32" wide)
Sure it wont rail as good, but it will be easier to turn, easier to catch waves on and overall a more enjoyable experience.

I personally ride a 8"4 X 28.5 105L performance.
But enjoy a 7"11 x 110L on a lot of the days.

Obviously the "tomo" style changes things a lot but for now, thats how i see it.