I disagree entirely, and I think the conc nades are very good as they are. They're the grenade you want against Jedi or Sith, the ability to prime them makes them unpredictable and harder to push. I see alt frags get pushed all the time even in close ranges, and when you're slightly further away it becomes extremely easy. If you and the thrower are so close by that it becomes nearly impossible to react, you still have options - be acrobatic and use your force jump. Get close enough to him and you will both be knocked down if he decides to throw, ez win. As for gunners vs gunners, they all have access to grenades or other knockdown abilities like blob, so it makes no difference. Personally, I always to prefer to take dodge or other abilities when available over frag grenades, as they're hardly the instakill weapons of mass destruction you imply they are and you can only use them once or twice.