Focusing on just the player, it's a great option.

• One time payment for advanced features, no subscription.
• Extremely customizable; visually, the audio output, how shuffle works (totally random, or favor less recently songs)
• Sync - I just directly sync my PC media and playlist folders to my phone, told poweramp where the folder is, and it just works.
• EQ settings, per device. Bluetooth headphones have a different curve than the bluetooth car. You could do per song if you're ever so inclined.
• support for high fidelity audio if your device supports it.
• Android Auto Support
• "driving mode" support (when using maps on phone)
• support for internet radio stations.

Well, I can say that it's worth it. Once you tweak the settings a little for your device, the only thing that sounds as good is neutron, and neutron is a hot mess ui wise. If you use a device that has its own on board "hi res" hardware, there isn't anything that's going to sound as good, even usbplayer pro (which is better if you want bit-perfect playback only, but it doesn't seem that's your priority) or neutron.

Mind you, this all assumes that you're chasing "better" sound in the first place. See, android's native sound processing is what most players will use. There's only a handful that do anything else at all. And it's that sound processing that's going to be your main limiter in chasing an ideal.

If you aren't going to care about any of that, then literally any player on fdroid is going to sound the same in general (the last I went through them anyway). So you're picking by ui/ux, which is a different thing entirely. Now, I prefer poweramp's ui as well, it really is laid out almost perfectly for my wants.

The licensing for non-google usage isn't onerous imo. Nor is it particularly expensive.