It's just sad that Cisco/Carlos is leaving mid-season. We'll see what the next 3 episodes bring, but so far his exit story doesn't seem very compelling -- he's just leaving. But I suppose a 'boring' exit is better than getting killed off, or not having an exit story at all (Wally, Season 4).
I've actually always wanted to see Rainbow Raider again (although, didn't Cisco choose the name 'Prism' instead?), so I'll take a new version. I hope they do something creative with her powers, so it's not just the same as last time.