When I play my Tempest, I don't feel like I have a new class mechanic. I just feel like I have a few more AOE cooldowns, and that's about it. More damage cooldowns aren't interesting, and I feel like it would have been mutch more interesting to make something like lingering buffs that slowly build up while we're in their attunement and slowly decay while we're not in it. For example, you'd build more and more power while you remain in Fire attunement, you'd build precision/ferocity/movement speed in Air attunement, health regen in Water, toughness in earth... All of which would become weaker when you're not holding on that attunement (think Cliffside Hammer mechanic).
Even overloads could remain if this is integrated, with something in the order of "overloading consumes all of that attunement's buff stacks and you can't build up any of it while your overload is on cooldown". That would actually feel like you're releasing your accumulated power.
That was just an example but the idea is that I feel like instead of simply having to wait (and waiting is never an interesting mechanic) 4 seconds to access to a boring channeled AOE, we should have something that would emphasize the "stay in an attunement longer to get benefits", while also pushing players to switch attunement at some point. New interractions between your attunements depending on the order and duration in which you swap to them instead of "spam Air overload with Fresh Air".
To conclude I feel like Tempest has a lot of potential, and I'd love to find a DPS build that doesn't relly on that fresh air thing... I'd like to feel mechanically competent when playing it. Is this too mutch to ask?