I haven't exactly done any professional writing (though I was just published in a conbook, woot!), but when I have passed my stuff to people for feedback I've tended to adopt a policy of, "If it's one person saying it and I don't necessarily agree, I'll ignore it. If multiple people say it...I have to do something." That said, I haven't yet found myself in a situation where I only had to deal with one editor who I could safely assume knew what they were talking about. Cloest I've come to that so far is my parents.