interesting, I imagine all those sets up you heard had a decent flat response along the spectrum, and still, you did not like them much; but, do you like bigger speakers that can handle sub bass frequencies well?, right?
First, I don't want to claim anything beyond how I perceived things on this matter.
But in the different set ups I hadn't seen any room measurements, but the claims were "I've done a lot of work and integrated the subs seamlessly." I didn't find it to be the case. I often found the subs still too prominent. I surmised that many who get subwoofers, and who may even pay lip service to neutrality, still want to hear the subs they paid money for and goose it enough until "yeah, the suboofers are there doing something" and they just get used to that. Just conjecture.
That's why I figured maybe I could dial them in to my own satisfaction. I was frankly amazed at how close I got to a seamless blend. But in the end I preferred the punch and tonality of my speakers without the subs. I'm used to floor standers, like my current Thiel and Joseph speakers, that go down to around (rated) 35Hz.
I've also owned floor standers that went down to 25Hz.
I do live with a bit of a bass boost though which can rear it's head. It's just that I find the speakers sound tonally more like the speaker I liked, that I bought, without the subs. They changed with the subwoofers in a way I didn't care for.
(BTW, I'm also used to hearing the sound of professional mixing studios which have subwoofers, all pink noised and dialed in. They sound amazing, though admittedly when I'm in the studio I'm not really concentrating on the same things...e.g. are the subs perfectly integrated?...but more about the creative aspect of the sound we are working on).