And you remember few occasions where the most quickly posted answer wasn't the most useful one for the problem you searched for?
Indeed. But with the new ordering (assuming I was using it), I'd still have to read all the replies, hence my doubt that it would be an improvement over the old ordering.
You mentioned "Anonymous visitors and new (registered) users are the ones who would most benefit from showing notes sorted by reputation instead of by time.", but didn't explain where the benefit comes from.