There seems to be a trend to answer questions under the assumption that comments >600 characters deserve to be posted as an answer. Often such 'comment-answers' are grasped as an opportunity for a lengthy discussion about the shortcomings of the question, the rules of Biology.SE, tips for good questions, uncertainties in the presuppositions and what not.
Without criticizing the actual content, I nonetheless think that fluffy comments exceeding the character limit should simply be shortened, split up in multiple comments, or taken to the chat room. Answers should be reserved for answers, not for discussions on the question.
Is there an established unspoken consensus about the use of answers for long comments? And what do folks think about the (ab)use of answers for lengthy comments?
Some recent, random picked examples (nothing personal, please avoid question-specific discussions):