Combat trade-offs with CHAMPIONS would be much more fun and difficult.
Instead of simply stunning the champions to DPS them, how about a trade off that keeps them difficult, but makes them more interesting. For instance:
Overload: Energy recharges, but normal attack patterns.
When stunned, the champion loses its recharge and is vulnerable to attacks, but THAT's when it starts spamming its teleport and/or attacks.
Barrier:Barrier up, normal attacks.
Barrier taken down, loses mobility, very weak to crits, but much higher attack rate.
Unstoppable: Massive defense, normal aggression and power.
Mod takes away defense, but the enemy becomes much more aggressive and can't be staggered. Their attacks become much stronger.
Summary:
These kinds of trade offs would make champions a LOT more fun. Even people that don't like champions would likely enjoy these because they turn champions into more than just a used mod slot.
Think it over, Bungie. Take your time.