This was my favorite Flash episode so far I think. No forced comedy, the villain wasn't cheesy like many that came before, the storyline was interesting and none of the characters really got short changed. Iris was actually bearable and Cisco was slightly less annoying than he usually is. He's still one of the most annoying characters in the history of Television for me but he was almost tolerable in this episode.
Caitlin should be the female lead, I know she's supposed to become a villain and she's probably never going to be with Barry but she's just the best actress on the show by far. Her and Barry are great together. I'm not big into the romance thing, I normally couldn't care less but they just work together and I find their scenes more interesting. Probably because Cisco and Iris suck so the less of them the better for me, but also because Barry and Caitlin just feel more natural on screen together, they work well off each other and seem like real characters instead of scripted ones.
Really good episode, hope to see more like it. The comedy was more organic, the tension was more organic, the character interaction was more organic, the storyline was interesting. It was just a very balanced episode that felt more natural than alot of the previous episodes.