I have a couple of imminent projects that will need some type of multi-site support. One is a large project that will need to share data between at least 3 sites. Where data is entered in one site and displayed on all. I've setup many sites in EE with MSM so I'm familiar with that method but never done this with Craft. I have read a few articles about how to set this up using the local function and modifying core files. I've also read about how this will be built into Craft 3.
So my question is - what route would any of you recommend taking? If I use the locale method will that the work be invalidated when Craft 3 comes out? Or is it advisable to go with the Craft 3 alpha hoping it's stable enough for production? I'm not sure when it will be released or if plugins will be compatible.