ICE is about the most automated stitching program around. The minimal controls make it easy to use, but also the most likely to fail completely given input that's too complex.
Hugin is at nearly the opposite extreme: though it has a wizard that's intended to help keep things simple, it gives you nearly infinite control over the result. On one hand, you can do almost anything with it, and handle stitches the ICE probably won't work with at all. At the same time, most stitches will take more work, sometimes its optimizer will screw things up completely (e.g., rotating one shot by 90 degrees), and you have all sorts of places you adjust things to the point of mangling everything.