@hilde45
My opinion, or perhaps hunch, cuts a middle ground between what your dealer is saying and others here. I can see his point, and that of folks like sksos.
My room is 13' x 15' with a wide opening to the hallway. The Perspectives certainly have no problem filling that room. They sound enveloping and dynamic.
HOWEVER....they are small loudspeakers for a floorstander. Physic is physics.
And I do hear the limitations sometimes. Mostly that occurs when I have the Perspectives on playing loud while I'm listening from outside the room, or just down the hall from the perspective (9 feet) in my computer room which is open to the hall. In those cases it feels like I can hear the limits of the impact from the Perspectives compared to my Thiel 2.7 speakers. The Thiels are rated to 35Hz like the Perspectives, but the Thiels are a 3 way with an 8 inch woofer. The Thiels sound more solid, authoritative and "wall shaking" when cranked. The Perspectives less so, almost a bit bass shy. That mostly changes as soon as I walk in the listening room and sit down. Then the Perspectives mostly make up for this and the bass is very punchy from the listening seat. In fact in one way more punchy than the Thiels...the Perspectives bass has a warmth that reaches out to the seating position so that I can feel the rhythm. Bass on the Thiels tends to sit back a bit more in the mix. Yet the bass can also seem a bit more solid on the Thiels, sometimes a bit more convincing when asked to really produce a sense of power like heavy Rock, big orchestral etc.
How this would all translate in to a big room? I guess for one thing it would depend on your seating distance. Before I bought the Perspectives I demoed them a few times at my dealer, and that was in an open show room. Not super wide - I'd guess maybe 15' wide? But very long and open...I dunno maybe 40 feet? I listened to the Perspectives both on the short and long walls of that room and never felt wanting for bass.
BUT...I do think your dealer has a point that the Perspectives are a smaller floor standing speaker and no doubt other larger speakers in the price range could offer more scale and impact.
Ultimately when someone is saying something like the speaker is "too small" for a room that rests on a personal subjective criteria. It's like asking "is X speaker satisfying for rock?" Well, one person may find it is, another won't. So will the Perspectives be satisfying in a big room? Maybe not for your dealer, but for you yes.