I just spent a good while reading this thread and I thought since Empty Places and this particular scene are my favourite of the whole season, I thought I'd give my comments on it.
I can understand why everyone felt the need to attack and Buffy about her plan. It was a dangerous plan, and they had just lost two more potentials at the vineyard , and before that. They felt nervous about going there unprepared.
Buffy's mistake was not carefully thinking about how she was going to execute this plan, it was clearly a plan that was not going to be thought through properly. Calib and the first and those ...(forgotten the name) had been waiting for them and well , look what happened in Dirty Girls.
And let's face it, Would you have wanted to go back into a dangerous situation with a reckless leader? I know I would not have. . A proper call would have to done some survelliance on that place at least before gonig back a second time. The one where Faith and Buffy are out checking the place, that would have been a perfect scene for them both to get a feel for the place.
Back to this particular scene
The show down was great, everyone will interpreate what they thought of this differently , I thought it was great we saw some sort of verbal fight between Buffy, the slaves (err I mean Potentials lol) and her friends. It was about time someone stood up to Buffy and questioned her decision making. Before the fight at the vineyard, there was something about Buffy's leadership/decision making that seemed to be not quite right. It was all about her. It was not about making the right decision for what was best of the group, even with the potentials. When you make decisions like this , especially when she was gambling with young girls lives, she should have considered the impacts of her decisions and their consequences. And this is what everyone was worried about - how she could act so irresponsibly..without thinking? And during Season 7 she'd demonstrated that.
It seemed Buffy was not clearly understanding their concerns. It was very one sided to her and she wanted it to be her way or no way.. and she was not willing to hear out other ideas and that was a shame because I thought Buffy should have least given some of the potentials, including Kennedy, some legwork in bringing up ideas on how they could have best executed the "plan." if they had to go back again...
Giles attacking Buffy with "Didn't you say to me today you can't trust us? Maybe there's something there that should be addressed." was a great way to start the attack on Buffy, but I don't understand why Buffy was being immature with her comment about Spike. Even though it did seem from her POV that Spike was sent away but I would not have thought Giles would have done this on purpose.
Dawn was a little cow here, how could she kick Buffy out of the house? I mean seriously, she's the one that doesn't own it, what should have happened was Buffy go upstairs and rest, it should have headed in that direction, Dawn had no particular right to kick her own sister out of the house. She sat back and watched everyone else attack her sister, and then she thought 'hey since she doesnt agree with us, I'm going to kick her out'.... She should have at leat somewhat voiced her concern to her sister privately... along with Faith,Giles,Willow, there was no need for it to spill with the potentials. (the trusting and the decison making/leadership baddy waggon conversation).
It was a really dramatic scene from my point of view and I thought it was handled well, except for Dawn.. It was probably the best thing in season 7 I loved, and I happen to love season seven more because of the hidden tension that was esculating throughout the season.