It was hard on Buffy but it also gave more meaning to all of it between her being in Heaven and the greater emphasis on the Powers That Be in Angel. Not only was it a great storyline to have her dealing with being torn out of Heaven and then choosing to live for those around her but then again, she'd always been told "death is her gift" which she thought was a croc. Then, she finds out it means Heaven so now she knows there is a light at the end of the tunnel.

Actually, it'd be pretty neat if Jack gets caught in that the darkness is a lie he started to believe himself because it was better than thinking he'd never be able to die and get to Heaven or even worse...that he feels he could never be worthy of Heaven/Elysium Fields/etc after everything he's done...