The big problem with upgrading exotics resetting talents were these two issues: - re grind to reactivate exotic perk - re grind to get back to max level In TTK: -All exotics start with their exotic perk -all exotics start with level 40 damage TTK clearly addresses it. As far as the perk trees that is deeper customization awarded only hen you've acquired further experience with the weapon to figure out how exactly you want to customize it.