I own a lot of written erotica. I have only written one review for Eden, though. It's, IMO, harder work than a toy. I take notes while I'm reading the book, then compile them, and then read things again to make sure I didn't leave out anything important. And you do all this without giving away the good parts of the book or stories.
I can't even think how I would review DVDs. "Um, they met, they sucked, they fucked, they came." It's pretty much all the same, with some exceptions.
Audio review? Boom chicka chicka? (ya know, that porn guitar sound.) I have NO idea there were that many "erotic" audios.
I haven't gotten that far in the catalogue I guess.