Daniel - I'll probably eventually get torched by the burn-in afficionados, but I did survive a prior thread that had lots of good comments and links. The one link that I'd found a while back and that does influence my thinking just a wee bit is this article by Tom Nousaine (
http://bruce.coppola.name/audio/BurnInLegend.pdf).
I'll leave it to folks like Mr. Nousaine who are generally held as expert and objective to do the tests and report the results. I'll also admit that I fall closer to the "if you can't measure it then it's ain't there" camp than not (truth in advertising notice: biases have now been disclosed). I do tend to like the argument that if it's not offered as a product differentiator by the manufacturer or an added-cost service by a dealer then it's not really real, but that's probably just 'cause I typed it...
You can probably find that prior thread by doing a search in here on "village idiot" - that probably appears more than once where I've been involved (as in "Hi, my name is Tim and I am a village idiot" ;-).