Waves is good coin and incredibly helpful but it is not new Ethereum. Their decentralized exchange is still unusable, no quantity, too many bugs. It's promising but Sasha is operating too slow. I don't anticipate large alterations in short term.
It is true that waves does have some issues but the price is too low now and i would grab some coins if i am an investor rather than jumping into Ethereum when the price has seen a good rally ,i would prefer Ethereum based coins and a decentralized exchange to trade my coins.
I think they both are strong and they will grow very fast in the near future. I am trying to invest both eth and waves. If we compare technical infrastructure, ethereum is more solid as it has already proven by hosting many kind of different projects.