I have a budget that I'm trying to work with, and those other items are all clearly portioned out and I'm doing research to try to get the best quality within each range.
The reason the present question came up was because I do have some money apportioned for "power" and I'm trying to get a sense of how much to spend there. Obviously, in any budget, some money can shift from one category to another, and so this question of "more power or cleaner power" is about figuring out how to judge these two categories against one another.
My conversation with Jim suggested that a very reasonable amount of power for these speakers would be 30 wpc, and others I have spoken to with a lot of knowledge has said that doubling this amount of power to 60 wpc would give me a lot of headroom. The recent suggestions (of 100 wpc and even more) are probably correct in theory, but I have a budget which needs — as you point out — to pay attention to DAC, preamp, etc. To keep adding power, way above and beyond what the speakers needs *at the cost of the other categories* is only an option if I have an unlimited budget — which I do not.
I would suppose your suggestion of what to concentrate on does *not* imply to spend zero on power, cables, room tweaks; so I guess I would be curious what proportion of your budget you spent on those things, if you kept track or remember.