I remember watching the first three episodes, finding it watchable yet altogether forgettable. My views soon changed when Spartacus entered The Pit, stopped feeling sorry for himself and started developing as a character. Since then the series has gained momentum and has stepped into its own.
"Old Wounds" acts as a lead in for the last two episodes of the season, and it does that job perfectly. The sexual content is scaled back and comparatively, the violence. There's only a few minutes devoted to the arena, and hoo boy they are sweet. Crixus makes a triumphant return and gets his sandals pretty messy in the process. We realize how skilled Ashur is at deception, and find that Batiatus is more devious than he seems on the surface.
Finally we come to Spartacus himself, who finally comes to the realization that his enemy is not himself but instead those who hold him as a slave. I enjoyed that this revelation came not from an outside source, but within his own mind and reason. He has really formed into a solid character.
Here's hoping that when the revolt comes, Crixus is on board and Mira becomes his new love interest. Well, one can dream.