bespangeled
Scooby
Personally, I find Spike helping Buffy defeat the First is the best way to make up for his past mistakes as a soulless vampire. Instead of moping for centuries or going around the world to apologize for hurting and killing people's relatives and friends, he's actually doing something useful with his soul and vampire strength. Actions speak louder than words and Spike proved that he can be trusted and relied on.
I completely agree - OTH, Spike has an edge. He has Angel's experience to draw on. Spike knows that a vampire can have a soul, a vampire can survive with a soul, and hence he knows this is a viable option. Spike also had a purpose, which Angel lacked. Spike got his soul to be able to trust himself not to hurt Buffy and to make reparation for hurting her. He had a few months to process, then he was part of the battle, and then he was burning alive. The fact that Angel was the first vampire with a soul and that he was cursed did not play to his advantage in a lot of areas.