I own an SHD. DIRAC is easy to use once you get the SHD setup, but the setup can be a real PITA. If you're used to AVR style room correction and setup, and you're not used to using a computer to install drivers and software and do firmware updates, then it is not as easy as getting out of bed. I would hate trying to explain to my parents how to do this kind of thing. It wasn't hard for me until I tried to run DIRAC for the first time and it didn't recognize the SHD. I followed the instructions to a T, uninstalled and reinstalled multiple times, and searched for and found people complaining of the same issue on the miniDSP forums with no solutions available. In the end, the only way I got DIRAC to work with my unit was by using a different computer. I have two computers that work with DIRAC and two that do not, all running Windows 10. Updates seem to have made it more likely to work and also installing on a fresh OS without previous miniDSP plugin installations.
Other then that I like the SHD quite a bit. I find that Volumio totally sucks with any source other than Roon though. I own multiple miniDSP platforms so I'm accustom to how their plugins work and I really like their flexibility. The SHD should come preconfigured to work right out of the box, just remember that input 1 is left and input 2 is right. Output 1 and 3 is left, and 2 and 4 are right. At least that's how mine came if I remember correctly. The plugin settings are constant across all inputs, so changing inputs does not change DSP settings. I wish you could rename the inputs and set gain for each but that's not an option currently. They did add the option to turn off inputs though which is nice.