The new Ek success corner punches are designed to punch the straight edge of the paper and the corner. Because of this you have to line up the corner carefully. However, even after turning the punch upside down and right side up I could not get a good punch. I bought 2 other punches from the slimline series (circle and border punch) and both worked well.
I bought this hoping to get a little bit different roundness on the corner of my pictures (different radius than my regular corner rounder). Unfortunately, I can't get it to work on the corner of a picture or even the corner of thin paper. It works best if you are trying to cut out a little "photo corner", where all sides of the punch are cutting through paper.
It's hard to explain, but most corner rounders only cut on the edge where the curve is. This is more of a "cut out a shape" kind of punch, that cuts all the way around the 90-degree angle and the curve. So if your paper / picture doesn't go beyond the 90-degree angle part, there isn't enough tension on the curve part for the punch to actually cut. It just smushes the corner of your picture through the hole without actually cutting on the curve.
The confusing part is that there are dotted lines on the back of the punch to help you line up the edges of your picture/paper, and ridges on the inside of the punch, so it appears that it is supposed to work like a corner rounder.
That said, it is POSSIBLE that I got an older version of the product? The picture here doesn't look exactly like the one I have. Anyway, I'll only be using mine to make photo corners, not to round the edges of pictures / paper.
I just purchased this today and was really excited because I'm just starting to build my punch collection. I agree with one of the other reviewers in that it won't cut thin paper it just bends the edge. I found that I can only get it to work on cardstock and then it is very difficult to line it up to get the proper cut. This is going back.