Ugh... If a list of worst Charmed episodes were to be made, then this would definitely be a consideration.
I would perhaps put this a notch above the worst episodes of Seasons 1-3 simply because Rose McGowan is involved, even if her character, Paige, is acting completely idiotic. This is one of those episodes where one character is acting completely insane, and this time it is Paige, who gets her share of such episodes. The exposure issue isn't the obvious biggest issue with Glenn. What should be far more evident and important is the fact that Glenn can be KILLED by staying at the manor if demons attack. This very obvious and real danger seems to completely escape Paige until being directly faced with the real possibility at the end, which by the way is the one good part of this episode.
Piper is very much the hardcase in this episode, but as she says, that is part of her charm. Except for the ending when Phoebe tells the accused to embrace his gift, the entire Phoebe, jury storyline is about as painful to watch as any in Charmed's history. STUPID. Also, there was probably just too much going on with the whole rat demons being behind it and then there being demons behind them. I guess it was necessary to get us to the cool part where Glenn's life was in the balance, finally teaching Paige apparently an important lesson.
It was also something different that Glenn was allowed to know about the sisters. Of course, there are plenty of innocents that know the same, right?