The only real difference to recognize is that our experiences, opinions, and judgments are subjective, personal. And that is everything.
That we might connunicate using a shared language with shared meanings to enrich our conversations is in the end nothing -- an illusion -- despite what our responses and even calls might suggest.
It all makes me wonder if I've said anything here about the irrefutable difference that the 35" scale brings to the b string (the obvious one being that it is 1" longer than the 34" scale b string) to inspire builders to go yet another inch longer? What an unquestionable difference that would make!
I'm not going to get my hopes up though. Gotta stay real here.
That's a rather unproductive view though, since there are others here besides you who are also experienced, capable, talented, picky, etc, just as you are. Don't you think? Recognizing that others here state they have found different results.. that opens the door to discuss why. There must be reasons why, and most likely found in physics, not in subjective impressions.
WE all care about our tone, some of us very very much, in my case. I think we can communicate just fine using the shared language of English in this case, and being analytical, and try to diagnose the cause of our different experiences.
I suggested one very possible reason. Most bassists increase the thickness of the low B string to make ti sound better. I have always gone the other way, for the simple reason that a lighter mass, and a more similar build structure to the next string, makes it sound like the rest of the bass, and makes it sound better as you go up the frets into higher positions.
This is from a lot of experimenting. Like, a lot, recording, playing back, discussing with string manufacturers, and so forth.
So I'm suggesting that could well be the reason why I don't experience the tone loss at 34" scale on the B string that most people think is the crucial difference to 35" scale.
For "floppiness", the topic of this particular thread, I have always found that the string stiffness affects that more than scale length or string gauge. There are plenty of strings that are quite stiff, move notably less far when plucked, and allow for a lower action without buzzing... DR low-riders for example.
I should also note that I'm not very big - 5'7" - and have average sized hands - not small, but not big either. So for me, stretching to 35" and longer scale length is not comfortable, since for almost 40 years of playing 34" scale basses I know exactly where the frets are without looking, and 35" scale does mess with that. I can go shorter and work through it fine, but longer really messes with me. So that is a negative for me, and no doubt affects me outlook on the value of 35" or higher scale length. Also I can't play multiscale very well, from my experience trying. I'm too used to jumping around and playing my way, sight reading music and not having to look at my left hand, and switching to fretless.... all of which are affected, at least for me, in muscle memory by changing scale length or going multiscale.
I prefer 34" scale for that reason, and because I don't hear or feel anything lacking in B strings (or lower) at 34" scale.