I have an Oppo UDP-205 and downloaded the latest firmware last night (I didn't want to do the Beta firmware that was released previously -- color me nervous since you couldn't go backwards if you installed the Beta firmware). I already had a few files that were non-MQA (e.g., WAV files) and MQA encoded (e.g., MQA FLAC files) -- Beethoven Piano Sonatas performed by Robert Silverman. I purchased the download of these files specifically so that I could compare the two once I get an MQA capable DAC. After updating the firmware, I compared a few tracks and honestly, I didn't hear enough of a difference that I'm convinced I could pick between the two with any degree of certainty. Now, I will also say that this particular recording (MQA or not) never really struck me as being cream-of-the-crop-audiophile-demonstration-quality to begin with, so I don't know if it was a fair comparison.
I've gone ahead and downloaded a few comparison tracks from 2L's website and will be giving them a listen tonight when I get home.
I also own an MQA-encoded CD, the latest Camille Thurman Inside The Moment released on Chesky, and while the "MQA Studio" label did appear on my TV when playing back the Robert Silverman tracks via USB, the Camille Thurman CD did not display a similar label on my TV monitor during playback.