It depends on the length of time and how high the link is saturated. Short periods of 60%+ utilization may not be a bad thing and may be usual for your network. However, if the link stays at 60%+ for all of the business day then the link may not be able to burst up to full capacity when that capacity is really needed. Questions to ask yourself include:
Do my users notice when the link is saturated 60+%?
What applications am I running that may experience problems during periods of high utilization?
Am I adding additional applications/users that may cause or see problems due to high utilization?Am I seeing lots of retransmissions or packet loss on the links?
What are my utilization trends? Rising? Constant?