The episodic nature of P.A. works kind of, but it could have been much better. As PrincessVera says in her review below, "The plot could be tied together better, but isn't.". For instance, c22 ends on a strong note, and yet c23 feels almost entirely unconnected to it. In general, it takes Shiho way too long to make her mind up about whether she wants to stay as a P.A. or whether she wants to become a real actress. What could have been one or two decisive and strong moments was stretched out over far too many chapters.
To that, I have to add that I found the ending of v8 unsatisfying. But more importantly, the author put supernatural stuff into tons of chapters - that doesn't add mystery; it just kills suspense. Specific examples: Once in v2, once in v3, divination in v5, astral projection or something in v6c20, hand reading in c21 (plus an awkward use of multiple personalities), a string breaks to signify bad luck in c22, etc.
Finally, a recurring villain appeared, and Shiho didn't report them to the police for no reason whatsoever. As a result, more people got hurt or died in subsequent episodes...
This story could have been far stronger with a less episodic nature and no supernatural stuff. (And if supernatural stuff felt necessary, it should have been introduced as part of the setting, like Kyoko's vengeance in Skip Beat.)