Yes, HQplayerPro is great, but to really enjoy on the live conversion you will need a very beefy built that is dedicated to music. But there will be many things involved to make it sound good. The DX220 is totally capable of being used as external DAC - DSD512 from a good Build. Do I still prefer Xivero ? Yes, Offline conversion is better than on the fly ....however, you will be trading for a lot of memory.
I have just bought a DX220 and then an AMP8 from a fellow headfier. Currently using Neutron. I love tinkering with file processing and your post piqued my interest. I read a bit around DSD/PCM and started looking around for convertors.
I have a Mac so choice is a little more limited (freeware at least). My most common format is 16bit FLAC ripped from CD via XLD. I curated an 8 song playlist for conversion to .wav using vlc (a hassle as you have to name each file separately). TASCAM Hi-Res Editor only accepts PCM as .wav and will convert up to DSD256. I definitely noticed a larger soundstage, crisper and more detailed highs but also some digital distortion at the higher frequencies. THRE will only do 1 track at a time which is a pain but hey it's free.
I plan to rerip the CDs directly to .wav and then reconvert to DSD just in case the FLAC to wav conversion has introduced some noise.
Any feedback or suggestions would be welcome.