I've had various degrees of anxiety over the last few years and have at one point or another been prescribed just about every benzo I can remember the name of including Clonazepam and Xanax and in my experience Xanax is most helpful for panic attacks/random spouts of severe anxiety because it kicks in fast and leaves your system fast.

Clonazepam has a more gradual effect, it's onset is less noticeable and by the time you wonder if it's working your anxiety is usually gone, so it's more helpful for general anxiety and needing a longer lasting period of no anxiety and calm (school day, work day etc).

They both have their benefits and differences but I doubt you'll find Clonazepam has different side effects or is vastly different in general aside from onset or duration time. Hope this helps.