I recently upgraded to v3 and I am really happy with it. After configuring the interface to my liking, I consider it a big improvement over the already awesome v2.
I do have a problem with .opus files, though. After copying some tracks to my smartphone (Moto G4 Plus w/ Android 7), these tracks get listed in my library. However, when trying to play them, Poweramp says it cannot play the file. At some point though, these tracks could suddenly be played. I do not know, what changed. To investigate I copied other .opus tracks to my device and same thing: They get listed in the library but playing them is not possible. I then closed and opened Poweramp, rescanned the library and rebooted the device. No change. The tracks I copied first still play without problems while the others don't. But I have no idea why and what caused the change for the first bunch of files. It seems to me that there is an issue with opus support but it is not straightforward.