The first real testing of Ethereum's move to Proof of Stake is on the launch pad ready for take off.
https://www.coindesk.com/the-code-for-ethereums-consensus-change-is-now-ready-for-review/
This is a big step away from the energy intensive Proof of Work consensus protocol now in use. There is still a lot of work to be done including client side development and at least one hard fork to enable the protocol system wide.
It remains to be seen if Ethereum can make these changes and keep pace with the second generation platforms like NEO and TRON. Such fundamental change takes a huge amount of testing and development. While Ethereum "fixes" their platform, newer systems have learned how to do things better and represent a real threat to their long term plans.