After receiving the warning:
MetaMask: web3 will be deprecated in the near future in favor of the ethereumProvider
I attempted to use eth.js
But I am not convinced that it is production ready. Especially when they still have We are aiming for early January 2017 for production use as a goal.
It seems to be working for me, but I am not sure if I should continue with it other than to help with testing.
The warning seems to be pointless according to this answer