EOS is very exciting, but is many years behind. Ethereum has many projects being built on it right now and as some of them begin to bloom, so will ethereum's ecosystem.
I would say the rigidity of a blockchain like ethereum does make it less prone to manipulation. It's harder to update, but that also means that it is more difficult to control.
EOS seems to have a bright future with all that it claims, however, ecosystems take time to build, and there is still nothing to build on.
I wonder if bitshares and steem would be willing to jump on EOS, assuming it would be possible as I've heard it might be (I don't see how it could be such a simple transition, but maybe there will be an easy way to plugin). I think it would be good for steem, and bitshares, as they would both gain a lot from being connected to a larger ecosystem.
As soon as EOS launched in June 2018, it will be Ethereum that will be beind not EOS.
Guess we will see won't we. There is room for both in the world, despite what people think they have different use cases. EOS is something that could essentially be contained in and run as a sidechain of ethereum, the opposite is not the case.