For me its not about the bit rates or sample depth but the care and attention put into the recording/remastering process. Very few companies make dedicated recordings in each format, an exception is the label 2xHD which document the recording chain and use separate brand adc for the different formats, DSD vs PCM, and so you can expect to hear differences due to the different ADC as much as the different digital formats. I suspect most multi format releases are recorded and mastered in a single format at a single sample rate and then converted to the other formats. The conversion is not perfect and this is easy to demonstrate. If you take a very low frequency square wave and convert from 44K to 88K or go the other way the square wave is not preserved... conceptually you just remove half the samples or double each sample but in reality its a fast Fourier transform and digital filters (c.f. Izotope RX)... and FFT does not work well at low frequencies and neither do the digital filters..
I hear less differences between modern dacs than I do other components like speakers, cartridges etc. I will say the early dacs were terrible. I have spoken with one hifi designer who admitted that of all the audio technology dacs have probably improved the most in the last over the period late 80s-2010s. certainly I could not find a dac I could live with until the late 2000s and then it was super expensive, now I am happy with a V90 with a golden reference LV psu... A very cost effective combo which performs as least as well as my crazy expensive (even second hand) DCS elgar plus, even if the v90 does not have DSD support, input options etc.
MQA is loss-full compression (it was original advertised as lossless but analysis has shown it is lossy) and has not really gained much traction, its potentially full of digital rights management and designed for surround sound. (https://audiophilereview.com/cd-dac-digital/mqa-the-facts-versus-the-fiction.html)... now its advertised as less lossy than mp3 and the DRM is not currently switched on... MQA playback requires licenses and so its unlikely to appear in open source playback software and even Jriver media centre has no plans to add it... I guess the license costs are too high.
Software like Jriver media centre can convert DSD to standard PCM and this is how I listen to DSD. The advantage of DSD is that the ADC converter is simpler and has less filtering. The disadvantage is that the playback requires more filtering (DSD generates a lot of high frequency noise) and its not easy to edit DSD... almost all editing is done by converting DXD 384K PCM and then converting back to DSD this process is supposed to incur no losses... There is very little music available in DSD format and even less thats only available in DSD...
My philosophy is get a modern dac, make the psu good and use the saved money on a better amplifier/speaker/headphone where there are still large performance differences... and don't forget to clean the connectors with deoxit or similar periodically. My mii T2 was recently sounding off colour, a bit lifeless and lacking detail in the mids and just sort of tried. I cleaned up the rcas and its back to singing again...The connectors on my van den hul first seem to love to oxidise a lot and rather quickly too... the cotton bud came out almost black from a single rca connector...
regards and happy listening
James