TBH the 15% fat stuff cooks better. You can drain off the excess if you don't want it. Not that I eat it any more anyway.
When I want really good hamburgers, I buy chuck in whole pieces, cut it in cubes and push it through the meat grinder. The result, as bd139 wrote, cooks better, and is much tastier.
On the subject of fat in cooking, in this country where I am at the moment, they fry their
pommes frites in duck fat. Sometimes. And, when something is made with duck fat, you pay attention, because it is going to be very good.
But the star of the show was the small deep fried fish far right in the pic. Veeery tasty. And, the Atlantic at La Rochelle was warm enough to bathe in.