I'm not saying the differences aren't real, I'm just saying they're not really practical for many players and audibly in most situations even less so.
For the "low C# theory" or slapping the low B through a 2x18 it might make a big difference, at least for the player in a tactile sense. For covering AC/DC through a 1x12, not so much, or if an instructor has one that's teaching kids that own a Squier starter pack it might just make it tougher.
For some people and some applications it's possibly "better", for some it ain't. No universal right or wrong. Despite the original post's sentiment, we can have some balance. I'm suggesting that "balance" includes not pretending the piano is really a valid direct comparsion, though it's a great way to illustrate the concept.
Ya know, with the amount of detuning going on in music, I'm surprised that fanned frets aren't more popular. I've heard more than my share of bands tuned to dropped A and I don't think any of the bassists really sound that good.
You're probably better off without them.