I’m a pretty strong “No” to this question. HQP is a playground for digital audiophiles who enjoy messing about with filters, but it is far from being a necessity in order to enjoy Roon or music.
Complexity. If you want it, signal processing’s got it. In the process of figuring out what is under the HQP hood you can find yourself looking at stuff like this. Now you don’t need to understand that in order to use HQP, but that is where HQP starts from and it’s not something that everyone who wants to listen to music has to get into;
Interface. The Kick-start guide significantly cuts down the learning curve, but Roon and HQP have diametrically opposed design principles. Everyone loves the Roon interface, but no one is going to look at HQP at a party and say “Wow, that’s cool”;
Sound. Not everyone hears differences between digital filters. Some people prefer the sound of PCM to DSD. There is no “right” or “wrong” about how people hear;
Convenience. The current integration asks much of the user. Disconnection issues will hopefully get fixed, but swapping between programs, possibly on different machines, is clunky. It’s also annoying to have to implement network connections through an NAA rather than RAAT.
And that’s why HQP has a trial. Try it and see if it is for you.
Now personally, I love HQP. It’s teaching me more about DSP every day and letting me feed my inner geek (well alright, outer too) to my heart’s content. I am thrilled to bits to have a Roon front end and an HQP back end.
But there are plenty of Roon users who will look at HQP, say “not for me” and happily continue listening to music. And the music is what’s important.
Edit: Disconnection issues have been fixed. Thanks to Brian and Jussi and everyone who reported issues the connection between Roon and HQP is now very robust.