Yea I like Bangel and Spaith and all but I prefer Fangel and Spuffy, mostly because their relationships could actually work out. Bangel while being such a tragically romantic প্রণয় story, we know it can't happen. At least not until Buffy's 'cookies', and even then it's only maybe. But Spuffy could work, now. Especially now that Buffy loves him.
Spaith is different, but I think that bangel is a much better relationship. অ্যাঞ্জেল helped faith so much, he never gave up on her. Never. And she really needed someone like that. In comparason with spaith, well I think spaith would have worked maybe back in season 3 when faith was 'bad'. They would have been epic together, kinda like fangelus. But I think that spike loves buffy too much to go for faith anyway.
So yea, I like Spaith and Bangel but in my opinion, they couldn't last like spuffy and fangel could.