This spell is not better than Snapcaster Mage as it doesn't have the 2/1 body with Flash, but in the right deck Mission Briefing could show even better results. Here's where you should try it out.
The beautiful thing about Mission Briefing is that it can target other spells with the same name in your graveyard chaining them into a long surveil train. At the end of it you will still have the chance to cast any other instant or sorcery in your graveyard. But for that you will need a lot of mana, of course.
This is another great deck for Mission Briefing that requires a lot of cheap non-creature spells in order to make a small army of elemental tokens with the help of Young Pyromancer.