Definitely well done. I happen to think it’s very flavorful that way. To each his own, really. Plus, for health reasons, it’s still safer to cook hamburger through. I heard Dr. Lorraine Day on the radio describing how the meat industry views hamburger as 4D meat: dirty, diseased, dying & dead. In other words, they use the worst of the cattle to make hamburger meat. The meat packers other little inside joke is, don’t wash the feces off, let the consumer eat it. So, if you choose to eat raw hamburger, remember what you’re eating in each bite, along with a host of parasites, that will at least be killed if you bother to cook the meat.