"11.5" hasn't technically been released yet, it only became released as RC today.
There are a lot of features involved, I'd look at the summary in this thread: NPM 11.5RC
A lot of things in NPM 11.5 are a long time coming (web based alert management, mandatory custom properties), so if/when it is stable enough for your company I would pretty strongly advise it. Updating for solarwinds products when you're paying for support isn't like planning on windows server updates.
