I'm not sure if it's been mentioned yet, but some of us may be aware that you can wander into the devils lair are you've completed the mission initially. My issue is that if you decide to take on the challenge of the spider tank, when he dies you don't get any item drops from him specifically that are worth mentioning. Perhaps when you encounter "bosses" like that throughout the full game, they should drop legendary loot that matches the level of the area the player is in. (Level 8 or 9 area and so on)