This depends on a few things. If your home is prone to hard water, then yes, a rinse aid will do you a lot of good. With hard water, there is a higher likelihood of residue, but the rinse aid will help to ensure that no water is left on your dishes (meaning no waste).
It isn't 100% necessary to use a rinse aid agent if you have soft water, but it could still benefit your wash cycle, so it is worth a try.