I don't like the Zagg products. The material is durable, no doubt about that. But there are two major problems with it. First, it has a tendency to discolor with age. The plastic they use gets yellowish over time and will also gradually pick up stains from other materials that come into contact with it. Second, the surface is not smooth but a subtle mottled texture that does affect the appearance of the display.
It's a shame really, because the material is quite scratch resistant. The secret is that it is semi-soft, stretching/yielding to sharp pressure instead of being cut. But it doesn't work very well for displays. It is also very expensive. Just buy Canon's replacement cover.