You know, it's EXCEEDINGLY handy that you've watched S5 of AtS, since so many Spike vids (& meta) deal with his whole story, which of course ends there.

Also re. Angel in general (and discussions in your previous post), then you might find it more palatable on the whole, since Angel is a very flawed hero compared to Buffy. So, although he often sets himself up as moral arbitrar, it comes from a place of having been the bad guy.