I can play advanced just fine as say, Oscar mike or Whiskey (insanely easy as whiskey cause of his life regen mutation), or any melee with life steal in their helix on basic attacks but when trying to do it with say El Dragon he just dies. All the time, even with a full defensive load out (including helix).
I would say that in advance its better to run common gear with negative so get early effects. If you go el dragon you NEED the HP regen, if you can get one with a debuff that doesn’t matter like reload, recoil. You can take your time.