So, maybe a naive question, but when looking within the *same* manufacturer/line of speakers, when/why would one choose a bookshelf/stand mount speaker over a floorstanding and vice versa? Let’s limit the discussion to a 2-ch music system, to take HT applications out of the debate.

Take, for example, the ELAC Debut 2.0: stand mount B6.2, or floorstanding F5.2. These both review extremely well by critics, have nearly identical measured frequency response and sensitivity, and use identical or highly similar designs, components, and materials.

Qualitatively, how different is a bookshelf speaker rated at 44 Hz - 35000 Hz, 87 dB @ 1m sensitivity going to sound from the same manufacturer’s floorstander rated at 42 Hz - 35000 Hz, 86 db @ 1 m?

The floorstander gets an extra crossover at 90 Hz, and so two of the drivers are dedicated to those lower frequencies; but that only results in an extra 2 Hz of bass extension. Enough to significantly change the sound, nonetheless?