E1.31 will allow multiple universes out from the one network, this makes it more scalable for the future. You may have 900 channels planned now but that will increase unless its a permanent installation for something where the channel count will never change.
You also have the choice of using a ECG-D2 which is an E1.31 to DMX bridge and gives you 2 DMX universes out, this will still enable you to expand further in the future by allowing you to start with the foundation of an E1.31 network.
E1.31 is DMX that is designed to run over IP and an Ethernet, so universes still apply, its just that you can now send multiple universes through the one network by using E1.31 which is a far better way for pixels.