Too much or too little power doesn't kill a speaker. This is a myth spread by people who are in the habit of killing drivers but haven't yet figured out why it happens. It's what the user does with the controls that kills a speaker. With good high end speakers, buy as much power as you can and then use a combination of precise gain setting techniques, your ears, and the volume dial to protect your speakers.
I personally woudn't be afraid to throw a good speaker up to 2 or 2.5 times as much as its RMS rating. It just means cleaner musical peaks with clean power even at high volumes, with no need for 'gain overlap', ie tweaking the gain to get more loudness at normal listening levels at the expense of some clipping. This can actually give you longer life and more pleasurable listening than not running enough power and fixing the problem with the gain or volume dial. Kind of like how a tiny 4 cylinder engine that has to rev and rev and rev to give good performance will wear itself out faster than a strong V8 that gives you all you need with just a light stab of the gas.
Not so sure about this analogy. There are plenty of 15 year old honda 4 cylinders out there running like butta, while plenty of lesser quality 8 cylinders have kicked the bucket with far less mileage.
Sure you can titrate your volume knob, but you are way more likely to run too much juice to a speaker with a higher-then-rated amp and eventually fry it then if you have an appropriately rated amp. At least that is my experience from playing guitar through 100 watt amps for 30 years.
I went with the dynaudios, by the way, and they sound fantastic. The amp is not underpowered for them, but, yes, a little more power would be more efficient. Can't complain about the sound though, it is crystal clear and plenty loud, sounds great.
BTW, turns out my speakers blew because of a terribly shitty install job at Sound Advice (now out of business). When they took them out they were loose in the mounts, rattling around, with melted adhesive crap all over the cones and magnets, and duct tape everywhere. It was criminal.
Here's a pic of that screw job:
That is why they sounded like poo, and why they blew out. Also, the wiring job was crap. That is all fixed now, thanks to the guys at Sound in Motion in Boston, who did a great job. Finally got my amp correctly mounted as well. The sound guys would also like to move and remount both the amp and the subs, but I don't want to splurge for that right now.