I have had burnt ends made from flat and I loved them. It is like everything else, a personal preference.
I have made from both as well. The point melts in your mouth, more of a fatty flavor, flat has a little more chew/substance to it and richer beef flavor. Which one is better is a completely personal preference. Both are fantastic, as are pork shoulder Burnt ends which is what we prefer both for flavor and cost.
(Brisket meat saving tip - if you cook a flat and it turns out "meh" you can often save it by cubing it into burnt ends and end up with a tasty emergency backup meal.)