(I had the Legendary Edition of the game when it first came out, which explains why I got this for free)
The Twin Mill Unleashed is basically the Mobil Twin Mill from the first game. But, it is better than what people think. For a Balanced vehicle, it does better than both of the base game Twin Mills it's based on. While it's not as good as it's brother, it still holds up so well, as it's the definition of what the very first Twin Mill should've been. Even if you don't like the Twin Mill because of it's overpopular and iconic status (not to the extent of the Bone Shaker), you'll like this one's performance.
Just be sure to slap on the Phase Inverter Skill for Charged Boost at Ultimate tier.