I'm using both Windchill Performance Advisor and PTC System Monitor.
The first since last year while the second since few weeks.
Although I am spending a lot of time managing and controlling Windchill PA, the benefits are far from what PTC promised.
Every now and then my data, regularly sent to PTC, is not uploaded (the last time it took two months for the problem to be solved by R&D).
The last recommendations received are six months old and the data on licenses usage, although PTC writes that they should be visible from version 11.0 F000, in my case appeared only after the update of my test server to the M030 build, because with the M020 they were not yet seen.
PSM sounds very promising, but it's quite complicated to understand if a person, as in my case, is only a Windchill administrator but has very little knowledge about DB management (Oracle in my case).