Too bad. That's going to be rough on the few remaining companies like Palstar that still used mechanical filters. My Palstar R30C has a Murata wide ceramic (also discontinued) and Collins narrow mechanical filter. Great combination for audio quality and blocking adjacent signals. I seldom heard the QRM and crosstalk other DXers complained about from WYFR when they were active on the funny bands, or LSB pesquitoes on 6925 when a pirate was on USB.
Some of the earlier web SDRs I tried couldn't quite match this performance, although the more recent SDRs seem to have solved that problem and offer some very flexible controls for digging out signals.
I'm not sure about the subjective audio quality issue. Very squishy area, especially with tube aficionados. Can't claim I ever heard the differences in radios, although I could in my guitar amps.