A service should use 100% CPU when loaded fully, anything else means you are suffering from bottlenecks that are actively limiting your throughput. Having lower CPU load because your disks are barely hanging in there is certainly not better.
If you want lower max CPU load, just limit its resources (e.g., CPU quota, cpuset limitation) or load it less.
If you want lower max CPU load, just limit its resources (e.g., CPU quota, cpuset limitation) or load it less.