Well, I disagreed with pdb, so maybe you agreeing with me was to be expected :-p. But I still feel I might have finally got something right around here :-)
We didn't really disagree, you just added a caveat that I think Mt Spokane puts in even better perspective.
There will always be nuance that can be added to blanket statements, but we are all in agreement that lifting Canon files is one of their weak points, and for all but the most knowledgeable user that fully understands the tradeoffs inherent in particular exposure choices the broad advice to get a well exposed RAW image will be easier to work in post.
Of course we can start talking abut specific cameras and the point at which they have digital amplification, we can discuss the finer points of base stops and where they fall on the iso range, we can talk about the tradeoffs between loss of detail due to noise reduction and loss of tonality when underexposed files are lifted to any serious degree. But I think that misses the main point.
For the vast majority of people , most of the time, using the 'correct' iso will give them an easier file to work.
P.S. You often get stuff right Marsu, don't put yourself down! Your knowledge of ML is probably better than anybody else's here, certainly your enthusiasm and promotion of it is. Your talk of the dual iso capability almost makes me want to try a 5D MkIII!