i subscribe to both, and have had both for years, dating back to WiMP and before Qobuz officially launched in the US. I’ve spent a fair amount of time comparing sound quality between the two, initially in the squeezebox ecosystem, now in roon, and further with the more widespread adoption of MQA. I’ve also compared both, and MQA to my own rips, which are mostly AIFF files (ripped years ago for use in iTunes).
my impressions have been pretty consistent:
Qobuz 16 bit sounds better than Tidal 16 bit (non-MQA)
Qobuz 24 bit sounds better that Qobuz 16 bit.
Local files in AIFF sound better than Qobuz 24 bit.
Tidal MQA sounds better than AIFF.
tl;dr: Tidal<Qobuz<Qobuz HiRes<AIFF<MQA
Caveat! when i speak of MQA, i speak of the full hardware decode. if your experience with MQA is limited to the partial unfold in Roon, as good as that can be, you have not heard what MQA is capable of.