When I go to audio shows and I'm sitting in front of a pair of speakers being demoed, I very often close my eyes to get a feel for the sound and try to ask myself what impression the sound is painting in my mind - big? small? high quality? Average? It often seems pretty revealing. I've sat in front of very tall floor standing speakers that, eyes closed, sounded more like crappy bookshelf speakers. And small speakers have sounded much bigger.
That said, generally speaking, not surprisingly many big speakers certainly sound much bigger.
I've had stand mounted speakers spec'd to around 40Hz at the same time as floor standing speakers spec'd around the same (and sounded so).
The stand mounted were inevitably two-way, the floor standing multi-way, with a bigger woofer. Though it sounded perceptually like they went similarly low in the bass in terms of what tones they were producing, the floor standing speaker just sounded more effortless and solid. Especially when I'd try to crank both to listen in the room, or down the hall, the stand mounted speaker sounded sort of like it was 'faking' the bass - and running out of steam. I could hear the notes, but they didn't have any solidity, punch and authority like the big speaker, which seemed to go louder with much more authority.
I love stand mounted speakers and always keep some around, but due to this experience over many years I gravitated to larger speakers for most of my listening.