I have learned a lot about "what not to do" from agent blogs, but it turns into repetition and whining really quickly.
I've also learned that as a non-USA writer, not only do I have virtually no chance of being represented, I'm supposed to find a way to get US stamps imported because the vouchers sold here aren't good enough. You know, because someone in Japan managed to get US stamps once. I felt that the comments about non-US writers were very ignorant of the way things work in countries other than the U.S.
I find a mild humour in the blogs whenever it's mentioned that writers should do careful research regarding the agnecies they query. How careful is careful? Obviously, you shouldn't query an agency that doesn't represent your type of work, which charges a reading fee, and it would probably help if you had a look at what else the agent represents. But really, what ends up happening is that one does a great deal of research into a particular agent and a week after querying receives a crookedly-cut form letter in the post.
And there is nothing wrong with INXS, but do you really want to know what someone you work for is listening to, like you're reading your teenage daughter's blog or something? As for learning whether the agent is the sort of person I want to deal with, I would prefer not to deal with an agent who links her blog to her business.