Yeah she made some disappointing vids. This was one of a few that I gave a miss. And from your mini-review I didn't miss anything. Her anal vid was also a total disappointment.
I've long argued that the AV industry/ecology is such that there's some kind of unspoken maximum quality ceiling. Maria Ozawa was quite the top attraction in her days so any vid with her would generate sales figure. And that's enough, it's as if the producers is afraid to make the vid too good (could the math be that an AMAZING dvd wouldn't sell much more than a good dvd, but could cut into the sales figures of other dvds released in the same time window?) So (1) Maria, (2) hardcore fetish, that's enough. We can't make the vid any better. So what should belong on the cutting room floor, or at best, as outtakes in a DVD extra now becomes the main parts of the film. We could put more effort and hearts into filmmaking but we are saving that for the performer were an unknown amateur.
Or perhaps she herself was at fault. She had the good looks and the will to make a great AV career. But she seemed to want to break out of some non-existent box and did a bunch of hardcore vids. But on one hand she failed to make a massive success in the hardcore realm and either she got bored with the mainstream AV, or the hardcore cheapened her value in the mainstream AV, either way she just quickly faded from view. There's no reason she can't be as active and as successful as Ayumi Shinoda or Anri Okita, who are the same age. Perhaps she wants to break into non-sex entertainment, but guess it's not panning out for her.