I use it to punch holes for my day runner refills. Second punch and the thing bent but I was probably punching too many sheets at once. Still if the pages fit in the hole punch it should be able to handle it and not bend.
I just bought 2 of these a week or so ago during their back-to-school sales. I found that they can easily punch holes through more than 5 pages. The holes that it punches are slightly smaller than the holes on notebook paper but still adequate. I am both quality oriented and value oriented and I found these to be good quality and a good value!