The key idea for that plot was quite risky, but it works very nicely. The great strength of the episode is to combine two plots that work as one : Prue's transformation into a man and the succubus case. Plus the great opportunities offered by the dating company, which allow Piper to make a move forward in her relationship with Dan. Prue's first minutes as a man are quite awkward, especially as she's got a very feminine face and a slight build that no amount of make-up can really disguise, but as the episode progresses you kind of accept that she's a man. The scene where "Manny" practises being manly by mimicking Dan is hilarious. But the best moment is when Piper dresses her down for becoming exactly the kind of macho man Prue couldn't stand. (The kind that receives a rather adequate punishment for letting his testosterone rule him).
This leads us to the plot with the succubus : it is original, and I appreciate the fact that for once it's Darryl who comes to the sisters for help, and not the other way round. The man doesn't even know their secret, but he trusts them to solve his problem. My only complaint here is that the psych-link between the succubus and Phoebe is never explained. Granted, Phoebe is more associated with lust than her elders, but it doesn't explain the connection. Just a passing mention of some forgotten encounter with the succubus would have done the job, I think.
This leads us to the plot with the succubus : it is original, and I appreciate the fact that for once it's Darryl who comes to the sisters for help, and not the other way round. The man doesn't even know their secret, but he trusts them to solve his problem. My only complaint here is that the psych-link between the succubus and Phoebe is never explained. Granted, Phoebe is more associated with lust than her elders, but it doesn't explain the connection. Just a passing mention of some forgotten encounter with the succubus would have done the job, I think.