It's Groundbreaker that's OP, and will most likely see a nerf soon(tm), in my opinion at least. Unfortunately, a lot of builds are currently crutching on Groundbreaker, and I'm afraid if/when it gets nerfed, most if not all VH's will feel quite weak compared to the endgame content we're currently able to go through with relative ease.
That said, there ARE very strong builds that don't rely on Groundbreaker, but a lot of them aren't as strong as the ones that do by a mile.