Ethereum currently using the prof of work consensus, which is costly, because it need a lots of computation power, miners use brute force to solve the hashes! In the prof of stake, the network will choose who has to verify the transaction, therefore it will be more energy efficient network! It will reduce the price and the time of a transaction! I think with this upgrade ethereum will be the winner over bitcoin! I expect a price boom after the upgrade!
Thanks for the topic!