I like the idea of the Exotic gear that buffs my class abilities. The exotic weapons don't feel all that special right now with everybody equipping the same ones, and I think it's a good opportunity to take advantage of classes/subclasses. I would really like it if there were some class specific exotic weapons or class specific buffs in the weapon upgrade tree. For example, what if killstreaks with a certain weapon increased the duration of the Titan bubble, or if a precision kill with one random bullet in an exotic handcannon had a chance of adding a round to the hunter's golden gun? Or what if there was nothing class specific, but the gun did the same elemental damage as your sublcass only when your super bar is full (but not activated)? I know this might be hard to implement, but it could add more of a reason to enjoy the class you picked (or encourage you to start an additional character with a class you wouldn't normally play with).