Riot while Chicago might be a decent step up for a lot of players...

You still have a long ways to go to match what Dota 2 has done in this situation

Had you left the old server up for west while making a server in the east that would have likely made a lot of people happier but that would still be leaving out one thing.

The ability to freely play on any server that you want is one thing that should be a focus for farther improving overall servers Most players would stay on the lowest servers based on ping but those who want to play against Koreans should be able to play against Koreans.

With both an NA west and the ability to play on any server everyone would be far more content with the server situation.

You want to play a normal with a friend from EU? Why should you have to make an account on another server to do so or spend a lot of RP to tranfer?

This Riot should be your long term goal when it comes to servers. While you have improved many things there is a lot of space to improve.