I believe the best way to use student-created inforgraphics would be as a formative assessment. Most of these infographics take research, designing, and special formatting, to be done properly; my students have access to online tools and many other programs, so I know they have the potential to so some amazing work. We need some more projects in our curriculum centered around research and student creativity. In an English class, to often the assessments center around writing and long papers. Infographics could be a great alternative to those mundane assignments.
I would weight an infographic project much higher than an Exit Ticket, homework assignment or quiz. Personally, I find the researching portion of formulating infographics to be the most appealing because it's a process that takes trail and error; the children will be learning as they're exploring. Again, I also find the visual/artistic aspect refreshing; it's not enough to simply read data, the power of an image or visual piece is phenomenal as it represents a strong message. Overall, infographics serves many purposes, and if I assign an inforgraphic assignment, I know my students would be utilizing multiple skills to achieve a successful project all at once.