This is a great episode that belongs among Season 3's best.
It was a stroke of genius to bring another whitelighter into the foray, namely a female with a long history with Leo. I would have preferred an attractive whitelighter to raise Piper's jealousy a Defcon or two, but at least this whitelighter is wonderfully annoying and uproariously sexually frustrated. The drill sergeant scene was somewhat unoriginal but still entertaining thanks to the sisters' petulance and Prue's ultra-low top. The whitelighter "talk" is hilarious, especially the sisters' reaction to it. Great writing there.
Our bad this week has the perhaps over-ambitious plan to actually wreak havoc in Elderville by killing whitelighters and thus making their charges vulnerable. Ames is similar to Matthew Tate in that he is a warlock who can steal powers and blink. He is a capable bad guy, though overshadowed by his plan. I found it curious that the Elders can't protect themselves from one warlock with a crossbow; they certainly can in Season 7. It was also quite strange that the sisters agreed to sacrifice Natalie. After all, how else could they ambush Ames in Elderville unless she died? Great vanquish though with all the sisters working together.
As expected, Phoebe can't hold her secret any longer and tells Leo that Cole is still around. Their scene at the club might be the closest Phoebe and Leo ever come to romance. As we saw in Season 2, Leo almost seems to be Phoebe's whitelighter even while being Piper's man. That bond is at least partially transferred to Paige once she is around.