Here's a real-life experience that, IMO, about sums this up:
I and a friend spent some serious seat-time with a pair of Aerial Acoustics 6T speakers (90 dB for 2.83 volts at 1 meter on axis; 4 ohms, 3 ohms minimum, low reactance; power requirement 25 watts minimum, >50 recommended) in a scheduled and well-orchestrated audition (same sound room; same acoustics; same day; minute or two between A & B listening sessions; same music; etc.). BTW: If you've got the dough and the right power source for these Aerial 6T, they are hard to beat, if that's even possible in their price range. The power source used for the first listening session was a MAC MC275 rated, conservatively, at 75 WATTS into 2 channels. Forget what the pre-amp used was but it, too, was a MAC. Minutes later, the MAC MC275 was swapped out for a MAC MA5200 rated, conservatively, at 100 WATTS into 2 channels. Within seconds (i.e. you didn't have to listen long or hard), it was quite obvious the MC275 was able to make those Aerial sing! Did they sound better or even as good with the MAC MA5200? NO WAY! They still sounded very nice. However, the beefier power supply of the MAC MC275 and the current it could provide was immediately palpable. It's not he WATTS. It's the power supply.