This punch makes extremely smooth, beautiful rounded corners, and the best part, is that it's fool-proof - you can't not get the paper in right, the guides ensure a perfect corner every time. Awesome. :-)
The punch works perfectly and the curve size is useful for any size paper. If you can't decide on which size to get for your project, get this one.
I'm already using this a lot... rounding so many corners on photos, tags, journal cards. Easy to use.