Fallout Automatron provided:
+New bosses(Ivey and Ahab)
+Creating your own robots from Scratch.More depth in moding Robot than even weapon moding.
+2 New dungeon.(Respawnable)
+Randomly generated varied enemies(No 2 robots are same).
+One new settlement.
+New companion(Plus you can make your robots as companion or settlers)
+One new Radiant quest.
+New characters.
+New Weapons and Armors and Power armor.
+Eyebot Workbench.
I do think little more end game content would be even better.