Big is good and big power too. I don't think that there is any substitution for either. I'll admit that I'd like to hear a system that does it all with 8 watts per channel but have never had the opportunity. Hard for me to imagine but Avant Garde works with very low power and I'd like to hear them too.
The last speakers I remember drooling over was a pair of Shahinian Diapasons, could have had a used pair for around $3500, 4 years old and over 10k new. The guy had already purchased a new pair for 12k and needed to move them along. He said the foam surrounds on the passive radiators was already going which kind of turned me off. I backed out without ever hearing them. If I remember right, he was using a receiver or integrated with 150wpc or less so it was clear where his priorities were. I was going to bring one of my Parasound amps to show him what power does to powerhouse speakers. I think he would have been surprised.
On another note, yesterday I biamped my AR9's and they really livened up. I thought they were pretty good with one amp but with two, they just get better. I just doubled the power to them using two Parasound HCA 2200 II's and I'm now very near the limit of what they are rated for. The difference in loudness is very minimal but when something is meant to slam, it slams! The bass is now pretty amazing and everything else is just clean and clear. I don't know why I waited so long to biamp them, they seem very happy now and had my son and myself a grinnin.
Bill