From the numbers, and from the history of the BVP line, my guess is that the Ambush will have the same inverted-bell core as the other BVP balls. As such, it seems highly unlikely to me that the Ambush will react like the Eliminator. If I had to guess, I'd say that the Ambush will be more like a polished Raging Inferno in reaction, but more pushy in the midlane.
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...formerly "The Curse of Dusty," and "Poöter Boöf" before that...