What is your experience with amp power?

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.

It seems the closest thing to a perfect world of amp employment is

via Bi-Amping

Mono-blocks>bi-amp

Even though the majority of one’s listening is done at around the 5 watt mark, I’m a firm believer of having ample power for transients. I also believe the quality of those watts make a huge difference  as well. Having that head room and power even with highly efficient speakers make for a much better listening experience.  No straining, no clipping, ease of presentation. In my experience my Tannoys are 95 db efficient and I drive them with a 500wpc McIntosh amp. When I first got the amp I thought it would literally blow me out of the room, but that wasn’t my experience. I think I’d be hard pressed to go down in wattage. 

High, clean current is most important. Too often watts are way over stated by a manufacturer and then when hooked up they sound weak. As always, the only way to really know is to place an amp in your system and see how it sounds to your ears.

My Audio Research Ref 75SE sounds bigger and better than my 600 watt ss monoblocks on every speaker I've ever played them with.

I think for most people, enough power is about 30 watts but amplifier power is not a good basis for comparing two amplifiers.  

"watts are watts" is a fallacy.