So I was thinking over the "tagging" system I added last time and quickly came to a couple of realisations.
1) Having a "string" based tag is limiting, what I really want is an object-based tag that would let me attach arbitrary data to the entity
2) Following on from this, I realised that this was akin to having a data-component
Now I'm thinking of splitting up my component system into DataComponents and BehaviourComponents. The key difference is that DataComponents would be just pure data attached to the GameObject. Behaviours are more like they are now, with a Start/Update method - I would also look more into beefing up the message passing so that the primary route to inter-object communication is via async messaging.
Why would I do this? The reason at the moment is very much down to the fact that I have a bunch of data associated with a component that I need to share between a couple of others. The way I'm doing it at the moment is to have components reference each other to grab the shared data. This feels bad. I could either consolidate them into one to try something new.
I'm thinking of doing the data component way.