I am a DRG, as mentioned in the letter of producer, they will not give the invulnerability for the jumps, it will only make the class imbalance not only for PVE but when it comes for future PVP too.

What I experience as one of those end-game DRG is definitely the casting animation of the jumps. DRG Jump skills fyi is not affected by Global CD, this makes it that you can actually time the skill usage in between the GCD skills.

Example, True Thrust --> Power Surge --> Vorpal Thrust --> Jump --> Full Thrust rotation.

By right we try our best to ensure that we have an action at every second, but the Jump casting animation is too long, by the time my Full Thrust is ready, I am still in the sky just about to land down the attack.

Besides that the casting animation makes me reluctant to use jump because you don't have enough time to dodge enemy skills. Fixing the casting animation will definitely be a strong boost for DRG in my opinion.