as outlined here) of an iPad can sometimes clear up a problem however it's not necessary to reboot them otherwise...they won't run any better or incur less problems. (Windows PC's can sometimes benefit from rebooting, however Unix/Linux/Apple OS X and iOS do not.)
Note that a full reset on the other hand should't be done lightly and only conducted when an iPad is frozen or won't restart normally (usually due to a rogue app). During a reset (or "dirty shutdown") the operating system isn't given time to carry out any current tasks before shutting down. Because of that there is a risk of data corruption. A reset should only be the "last resort" to get an iPad going again.