When I sold consumer electronics in the late 80's/early 90's, we avoided selling these like the plague, as the commissions, dictated by Gross Margin, was so low.
As was often the case with manufacturers that didn't sell a lot of bling, there's loads of hearsay idiocy that caused these effects. "Oh, it says 'Technics' instead of 'McIntosh', so it must suck, especially since I've never heard 'MASH'."
Well, I could bet as much money as I had that nobody would be able to distinguish any off-the-shelf CD player from the late 80s or later in terms of sound quality. Those stories are just based on emotional autosuggestions.
Back to MASH itself: the acronym is only "awful" in that it doesn't match very well what it's supposed to say: "Multi-Stage Noise Shaping." W.pedia can tell more about what
noise shaping is.
In the end, MASH chips were basically four bit DACs that didn't sound better or worse than any other decent converters from, say, Burr Brown or so. They were developed by Matsushita (now Panasonic), extensively used in Technics CD players and found further usage in Sansui and NAD devices, as well as—obviously—Panasonic professional gear.
If it is about CD players there's nothing wrong with one having a MASH chip. There are many other important criteria for choosing a CD player: visual appeal, build quality, features, access times, gapless support, etc. In this respect Technics CD players (at least the later ones from 1989 onwards) are pretty recommendable, as they e.g. use extremely fast linear magnetic CD mechanisms that allow TOC readings and track jumps in ≤1 second; the TOTL models also have many nice features (jog wheel, 20 block access keyboard, etc.). However, it still has to be said that those specific models were mostly released before the MASH era, e.g. the SL-P770. However, if you want one with all of that
and a MASH chip: go for the SL-P777. The front says "4DAC 18Bit", but inside they secretly employ a MASH DAC. Apparently Matsushita was not sure whether people would take it well that they now had a 4 bit chip instead of four 16 bit* ones.
*This is not a misprint: Technics used 16 bit converters but employed a pair per channel and slightly shifted one of them using a Yamaha multiplexer chip so that the total construct factually worked with 18 bits.