Outside flat is a decent roast, restaurants use them a lot for roast beef, beef dips and such.
You can cook them to well done if you really want it that cooked. Find flats that are AAA (Canada) or choice (USA) grade fir added maoisture and flavor.
We used AAA/Choice flats for making jerky in my butcher shop. Clan the outside, split the neck off where there is a large piece of nerve and liver skin, then slice against the grain. Makes nice big flat pieces with delicious marbling. jerky is really tender and flavorful.
Great for sausage making, grinding, stew, curing and smoking in large 1lb chunks, kind of like a pastrami.