You actually have a slightly greater amount of time taking the GRE via computer than via paper. I STRONGLY encourage a review of math concepts for the quantitative part.
That seems to be the weaker area for most people, not because we get stupid in our golden years, but because we truly don't use the Pythagoean Theorum in everyday living. Review your Verbal as well. Many grad schools want in the 50th or better percentile. You can always try the Miller Analogy Test (MAT)--some schools accept that as well. If there is a review class available, check it out!
I had plenty of tests in graduate school--don't kid yourself. Also, if you get anything lower than a "B", you may be talked to by your professors.
Good Luck!!! :)