Well, Zig can be beaten by a Falcon (P), or really any cruiser or capital with 2+ Proximity Charge Launchers (along with elite Missile Specialization) solo. And then the Zig itself combined with the Industry tree can travel 150 light years round trip (500 fuel + 50% = 750 fuel at 10*0.5=5 fuel per light year). That will go clear across the entire sector and back. And 300 cargo capacity is enough to carry AI cores and omega weapons back, plus the needed 150 supplies or so. Even without the industry tree, 500 fuel at 10 fuel/light year is a 25 light year range, which covers quite a bit of territory, especially once gates come into play.
If you're willing to swap what your single ship is at any given time you could always explore the sector in a Hound (finding gates along the way), come back to the core, and swap in the Ziggurat to clean up. Depending on one's goals, you can complete the entire campaign and unlock gates in a Hound without firing a shot. Go from Hound, to Legion, to Zig.