EOS is a promising implementation of smart contracts. I heard a very learned crypto analyst calling it out as the future of blockchain based smart contracts and asked his followers to sell all Ethereum and get into EOS. But one should be careful running after an unproven implementation over an existing working solution.
Why Ethereum is going up
Ethereum is already a proven implementation and it is being used by a lot of ICOs for token distribution as well as multiple partners are coming onboard. It has a strong technical team. They have scalability issues but one can not write off an industry leader and pioneer to give up.
Another reason for price going up is the integration of Ethereum on exchanges and upcoming future contract from CME. It will keep Ethereum prices high for short to medium term.
EOS price trends
EOS has moved up by 400% in recent weeks. They have still not completed the ICO and releasing 2 millions tokens every day. This will continue till middle of 2018. This will keep a lid on the prices. Also, they have not even implemented the project fully. The EOS tokens you are purchasing have no value on platform as it does not exist. You will have to exchange them to EOS tokens when they complete the implementation. So, current price rise is pure speculation play and even with all the promise it holds, it is not yet ready to replace Ethereum.
Disclaimer: It is not an investment advice. I am long on both Ethereum and EOS. Investing in altcoins is like investing in startups (98% of all startups fail). It is recommended that you only put the money you can lose in these investments.