For me the Phobia is stronger than the Impulse overall and closet ball in the Track line would be the Kinetic Emerald (might be a touch longer than Phobia).
All three balls are great rolling pieces, but the Phobia right now is one my favorite for a lot of lane patterns... I have sold a lot of these in the shop to various styles of bowlers and they all have loved the motion of the Phobia. Hope this helps...