I'm usually one of Alyssa Milano's harshest critics, mainly because I want to stick my tongue into an electrical appliance whenever she appears on screen. But, occasionally, she acts pretty well. This is one of the (few) occasions where she is good throughout, probably because her character name is in the title but, y'know, whatever...
The Three Faces of Phoebe sees the slutty one getting cold feet over her imminent wedding to Cole and conjuring up two different versions of herself, a free-spirited and excitable young Phoebe and an old, more experienced Phoebe, to decide whether or not she should go through with it. Meanwhile, The Seer continues her quest to turn Cole into the new Source and Paige gets a promotion at work.
The main storyline of this episode seems pretty pointless. Despite placing Alyssa, once again, in center stage, it doesn't do much to evolve season four's arc plot, instead leaving Phoebe with the moral that she has to make her own decisions for once, instead of relying on others. Yes, that's it. Alyssa is good in the episode and genuinely convinces, same goes for Frances Bay (aka "The Marble Rhy Lady" on Seinfeld) who gives a good performance as the older, more cynical Phoebe.
It was a good decision to turn Cole evil again as he's, to be honest, a boring character when not plotting somebody's doom. But it's a shame that the demon story in this episode wasn't that great. Harry Van Gorkum is pretty much demon-of-the-week material and does nothing to make his character Kurzon any more memorable than all the other Cole-related demons on the show.
This wasn't a memorable episode by any length but does give Alyssa Milano and Rose McGowan chance to show off their, sometimes underused, acting talents. Despite that, the demon storyline is easily forgetful and the whole "three Phoebe's" story ends up being kinda pointless.