The DR-MV150B and DR-MV100B were popular as early ATSC-tuner recorders, because their tuner-timers were a little less buggy than some other brands. Not a lot better, really, but people grasped at straws then so they became hot recorders. Aside from being not-terrible, there was nothing especially interesting about them that I could see. But then, I've never been fond of the all-in-one machines: those who did desperately want a combo seemed to like them very much. Since there are none leftover in stores, no refurb deals, and few used units on eBay, I assume most owners were happy with them.
The watershed year for many of these recorder brands was 2005, when all their hopes that DVDR would replace VHS as a mass-market TV recorder went up in smoke in the face of total North American disinterest. Between 2005 and 2006, nearly all of them gave up making their own distinct hardware in favor of surprising joint ventures with their rivals, or just signing OEM deals with generic mfrs like Funai.
The "genuine" JVC recorders pre-2006 were actually pretty damn good. They had a distinctive PQ that many loved and some hated, but at least it was something different to choose. Their Achilles Heel was a horrifically poor power supply section that tended to fail like clockwork whenever you set the timer for a really important TV event. There was an ambiguous extended warranty to fix it, but few owners were aware of this and just lived with the unreliability, seething until they exploded with rage on forums like this one. At the time, there were a couple of rabid JVC fanatics here who would cut their throats rather than admit anything was fundamentally wrong: they would post endlessly that anyone who had problems was hallucinating, making it up, was a "hater," or just plain too stupid to use a DVD recorder. As you can imagine, this was not helpful and just served to make JVC into more of a pariah. By late 2006 JVC moved to a very "meh" generic recorder design and by 2007 gave up and subcontracted LG to just slap a JVC label on their machines.
I once owned a couple of the 2004 JVCs, a DR-M100 DVD recorder and a DR-MV5 DVD/VHS combo recorder. When they worked, the PQ on finalized DVDs was about the best I've ever experienced. But they constantly crapped out with the dreaded "LOADING" paralysis and could not be relied on in timer mode. Too bad, because they also did a really nice job converting PAL discs to NTSC during playback, and the VCR in the DR-MV5 was really good at tracking dodgy tapes. Fortunately I bought them as "refurbs" so they didn't cost me much, I sold them off "as-is" without too much of a loss.