The question not asked is this: does Cisco 15.x support SolarWinds? The answer currently is no.
Currently you will experience high CPU usage under IOS 15.x. You will see memory leaks which eventually lead to Cisco devices rebooting. It may take a few weeks, and it may take a year for this to appear. The cause is poor quality within IOS 15.x. There are IOS updates being released often to address these issues, however they have not all been fixed. We have many SmartNET cases open regarding several of these IOS 15 issues. I would not recommend IOS 15.x in a production environment.
There is also a currently known issue where upgrading IOS and reloading will cause Cisco devices to fail due to memory issues. The issue is caused by bad DIMMS. Search Cisco for this known issue and be aware of it.