The episode itself is sad and I can't watch it again either.
The scene, right after W/T almost kiss as they're on the ground, when Willow's spell is broken, is gutwrenching in the way the cast members play it entirely with non-verbal cues.
The spell is broken and memory comes flooding back to them of their true identities as well as the fact that Willow put them all in danger this time by messing with their collective memory.
One by one, the gang get up off the ground and turn their backs on Willow walking away from her and she just sits there curled up in the foetal position and can't bear to lift her head to face Tara after having betrayed her once again.
It shows what we Kittens know about the versatility of Aly and how if any of us could fund a show for her, we would in a bloody heartbeat.