It says that the level 3 Tavern unlocks the "lucrative" treasure quests, and with a lvl 3 barracks you can assign more doods on farming missions. Along with Salvage yard lvl 3 I heard of people getting decent player gear to sell, though rare. TBH though most of the large buildings look to be useless. Any insight anyone, please?
Barracks are awesome you get endless missions for your followers you get so many of it you can put all your followers into mission and still have missions left. You need scout mission to unlock achievement for barracks 3. You get a bodyguard that will go with you anywhere and fight with you, it also levels up a bit. Not sure if there is anything else to it. Tavern you get a lot of beneficial items with buffs from what I saw along with items. Mage tower you get portals to some places to shorten your farming and stuff forgot what the rest was. I think all the buildings are very useful it just depends on your goals