I believe you can't know whether a message is sound until you've managed to work past/through your own strong feelings reacting to a message's pleasantness or unpleasantness. A heuristic which dismisses a message because of its unpleasantness or accepts a message because of the opposite is going to result in many, many false negatives and false positives with respect to message validity/usefulness. You can only pick apart a message's 'soundness' in the calm place that comes after emotion: where those feelings can be one source of information without their intensity overwhelming all the other information.
