Whatever your network problems, there are generally very readily available tools to allow you to troubleshoot the...
issues. Whatever you do, though, you must view utilization as a statistic based on when the network is actually in use. Don't forget Gate's law either; the speed of an application is cut in half every 18 months. This means that you will need faster and faster electronics including servers and workstations, over time to allow for the same relative speed from one version to the next. If you network is not healthy to begin with, your problems will only continue to worsen. Each increase in speed, change of application or network change should warrant a post implementation inspection.
There are many ways to optimize performance without throwing out the baby with the bathwater, so to speak. Optimizing what you have, upgrading what you have or potentially replacing what you have will assure that aspirin needs are minimized while stability and performance are maximized. Whatever you do, make sure that your electronics are manageable. If not, you will be looking for the proverbial needle in a haystack. These statistics will prove invaluable for your performance considerations.