No,...
(Maybe a moot point by now, 'cause this thread is old and topic's been covered pretty well),... but...
The Yamaha MD series (MD4/MD8) portastudio-clone recorders have an A/D converter which adheres to 16-bit/44.1kHz sampling rate, but it's the ATRAC data reduction that seems to drive people nutz, which (in it's day) was a HUGE source of controversy.
ATRAC data compression is not the same as audio compression. However, it's a scheme that bases it's data reduction on the premise that human hearing tops out at about 16kHz, also the idea that in audio a louder sound will mask a quieter sound, thus audio data that falls within those two ranges can be discarded. That's the only way they could fit any useable length of audio on that tiny little disc. This is what drove "audio purists" nutz. That, along with the rapid advances in technology, & the fact that MD and ATRAC was not marketed well, is why MD was short lived and ultimately failed in the marketplace.
Most people these days wouldn't touch Minidisc as a recording format, with all the other "linear PCM" format recorders out there, but if you don't mind buying into a "dead" medium, MD is alright for most people's needs, whether they believe so or not. Sometimes it depends on how cheap you can get into MD on the used market. Sometimes MD is a steal or a "sleeper" deal. YMMV.
I have a few Minidisc recorders, and they're alright. Despite the buzz and myths on MD, you can't "hear" the ATRAC compression. It's just the idea of "reducing" the data below the "16/44.1" (CD standard) that absolutely drove people nutz!

