@DayDreamer27 I don't think Spike getting his soul cheapens Angel or Bangel at all. I think Spike and Darla getting their souls back show the specialness of Angel making himself into a champion. It challenges the idea that the soul was a special privilege awarded only to Angel. The soul merely provides the opportunity for change.
I agree with you to the extent that the soul provides a vehicle for change. The only problem is when the soul afforded to Spike prompts an essential retelling of a story you already heard (except the first draft was better):
S6 spuffy doesn't cheapen Bangel. It highlights the distinctions between the two dynamics very vividly. S7 - that I still am not sure what Joss was going for there. Why the deliberate and obvious parallels?