Yeah, it's something I pay attention to, as well as impedance. I work in power delivery (linework), so I have a pretty good understanding of electrical theory hence my attention to impedance. While it makes complete sense to me that a speaker rated at 87db and 6ohms would require much more power than one rated at 90db and 8ohms, the sales guy at my local shop where I listened to Klipsch, Paradigm, Monitor and KEF stated that too many folks get caught up on sensitivity.
He mentioned the importance of capacitors in the equation- specifically he said that bass frequencies that require more extension while moving a larger mass require the higher, short term wattage that a capacitor will provide. He said, with regards to sensitivity and power, that if you are using large speakers with a lot of mass to move (really large drivers or several large/medium-large drivers) and listen to music with a lot of mid to low bass then amplifier power is going to be an important consideration. Otherwise, he said, most speakers (especially bookshelfs) will use fewer than 25watts continuously with short bursts of higher power. His case was made fairly well by the fact that he was driving the speakers I was listening to with the 50wpc Marantz Slimline AVR.
I gotta tell you, dude... I can research all this stuff to death. I'm almost thinking at this point to grab the Mini Monitor v7 along with the Monitor SE center, for a total of $600+tax and just be done with it. I did really enjoy the sound of those Paradigms. I'm just hung up on the what if aspect of not being able to listen to some of these other speakers.