Spike changed before he even got his soul back. Angel and Angelus were completely different people.

^ Agreed 100% with Grace.

^^ yeah I agree too!

I think the better question is who wanted their soul the most. People seem to forget that with angel it is simply a curse. He never went out of his way to get it. It is something that was forced on him. Liam's character was not stronge enough to over come the demon inside, while William's Character was so strong that it fought to kick the demon out of control of his body. I think that while it didn't appear that Spike changed that much it is a testiment to William's character that he got his soul back in spite of his deamon. Angel was a good vampire that never tried to change. I actually perfer Angelus to Angel.

Angel was better than Angelus

They both changed a lot though.

Angel's character changed completely. He went from disgusting, abnoxious and -!EVIL!- to quiet, brooding, and not, um, evil.

Spike's character still was basically the same. He just lost the evil, sadistic part.

Spike didn't change a lot... Angel and Angelus are completely different... Spike and Spike(us) are alike...

Angel completely changed. Spike not so much.

I think its debatable cuz they say that the person is nothing like the person he/or she used to be... but if look at angel, spike for example the vampire's personality can be the corrupt, opposite version of its human predecessor, or an expression of the human's hidden potential and have their vampiric abilities to achieve their goals without their soul.

So I think Angel changed dramatically...even though he had his soul returned by force and Angel really starts to change from his relationship with buffy, she helps motivate angel into becoming the hero he is though its already there...he just needed a push in the right direction like Whistler, Buffy, Cordelia each did for him though he is good.

Spike, i agree with this-is-my-name not much is changed personality wise just his morals and values have shifted and matured without losing the essence of spike's character.

Angelus and Angel are complete opposites. With Spike the difference is a lot more subtle. It was probably done deliberately to give yet another contrast between the 2.