It’s hqplayer 6 now. 
I’m sure Jussi has more refinements and optimizations in the works with v6.
To others upgrading, if you have any problems, send an email using the email from their support page! They will get back to you.
I ran into an issue with my lic file triggering an error message. I contacted via email along with a copy of my lic and Aapo was very quick to resolve the problem.