I know WvW is hard as hell to balance, I know that it probably won’t ever be balanced but to me this is a game defining and breaking issue:
Mesmer portals.
When a Mesmer teleports a entire zerg into a strategic location where they then build siege equipment and faceroll it’s a bit absurd, the 90 second cooldown wasn’t enough.
What I suggest to fix this is keep the 90 sec cooldown and make portals only usable by the Mesmer’s party (a maximum of 5 people including the Mesmer).
This will still allow ninja squads but will deter clear cut abuse of the Mesmer portals.