While Sven's departure was needed for the Princess to take his role, it always felt a bit like he was cheated (though if you consider the fates of his counterparts, the Kurogane Brothers of GoLion, he actually does pretty well). So this episode would be worth it just to seem him fly Blue Lion one last time. But this third season episode has a lot going for it.
Finally, we see Lion Voltron on Earth, something that just wasn't possible using GoLion footage, since, like Kurogane, Earth was no more after some early eps. We also see them actually interacting with Galaxy Garrison outside a viewscreen, and the throwaway lines at the start, when some technicians envy the lion ships, were just great. Added bonus : I think this was the only time Zarkon and Lotor didn't simply betray their allies.
I wish Fleet Of Doom had been this good.