I would have to disagree, Dawn got taken and Buffy literally went into a catatonic state, I think she would suffer more than Dawn would. Especially since Buffy becomes her mother.
Although Buffy had to deal with things that she definitely wouldn't have been able to deal with, she would have still ended up in debt, Giles would have left, the dynamic between the scoobies would have changed, and Buffy would be mourning the loss of both her mother and her sister (who is more like a daughter to her).
I know the trauma on Buffy from being dragged from heaven is very heavy on her but the fact that she failed to save someone who she loves so much would be heavy too, knowing that she could have saved her.
Dawn isn't Buffy and will react to things differently. Dawn has lost her mother and sister but Spike has also stepped into a father/brother role and Buffy's parental love for Dawn will make it affect Buffy more than it would Dawn.
I suppose it also depends on whether what would weigh more on her, the loss of losing perfect happiness or losing her whole family. I don't think that she would have had her epiphany about wanting to live though, because a very big part of that is down to Dawn, so we may not have got season 7 Buffy in the way she was.
Buffy knew Dawn was not her real sister and the monks had use her ...was Buffy love for Dawn natural in S6 or was it still part of the Spell left over from S5, when Buffy acted unreasonable and would have let the world end than have her non sister killed...by S7 Buffy has a conversation with Giles she would have let Dawn die because of what she had been through , as for Dawn no sympathy from me throwing Buffy out of her own house....Dawn is still a bitch