Managed to get through Area 51 in less than five minutes on our first try! 
 
Make sure you change characters in the Build hub when buying accouterments, specifically the base plates (the brawler from Raiders). 
 
Apparently, you had to play all the Story levels in Quick Play - so, played a few extra levels... About 60 of them.  Oh well.
 
Well, 100% complete anyway.