Is there any truth to this question?

Regardless of the speaker's sensitivity I have found not driving your amp too hard and having more power and headroom available is a very good thing. In my current rig a highly touted 70 watt tube amp was displaced by a Hybrid amp with 4 times the power. The more powerful amp was not taxed as much, and I think since it was not pushed, just sang with more ease and pleasure.

Extra watts and headroom can be a very good thing especially with large orchestral music and the like. Same is true for solo piano turned up to louder volumes.

Once you have enough power to get to the volume you need, it is more Power supply and current capability, not watts per channel.

I have never seen one question with so many variables. If everybody chooses the variables that makes their answer correct, then nobody is wrong.

Digepix,
The general consensus from those who`ve heard or own the YBA amplifiers is they are very natural. Their strenghts are realistic tone,timbre with an organic and very 3 dimensional sound. The emphasis is on music rather than hifi pyrotechnics.They are considered exceptionally constructed with excellent transformers and parts.It seems a product built for music lovers above all else.

Gon member Defstathiou owned krell at one time but finds his YBA components much better. He found the Krell sound 'robotic and mechanical' lacking the fluidity and flow of the YBA gear, not as natural. Like you he listens to a lot of jazz but says it goes well with any type of music.With your room size and music preferences The YBA would seem more to your liking.
Best of Luck,

The other thing I forgot to mention is that I have to sit near field < 6 ft due to being wheelchair bound and with the layout of my apartment. I don't listen too loud and with the music I listen to it's rare I push it anywhere near the clipping point.