I don't think the idea of ECS is fully baked at this point so it wouldn't make a huge amount of sense switching to it yet. The performance figures aren't really practical because they rely on using cpu cache rather than RAM to get those performance improvements and you have no control on how long a cpu will keep something in cache for because there is so little of it. It looks like ECS and the new job system were designed to try and solve the legacy issues of unity being manly single threaded and prefabs always generating cpu cache misses because of them being in a format that a cpu wouldn't cache meaning they are accessed from RAM rather than cache 100 percent of the time. ECS still appears to be flawed in that it has moved to the polar opposite. It is trying to make the CPU place entities directly into cache to avoid cache misses by trying to put stuff directly in cache but then it is in effect using cache as ram instead of as cache. Games simply use too much memory for this to be practical. The engine and opperating system should be the one deciding what to cache not the user. For example would you want a cpu cache to be filled with spline data ? Whats to say that you have other functions that need that fast access more and if you are running lots of assets that are all using ECS to write to cache then they will simply overflow into ram anyway ? The demo Unity is showcasing with all those instance objects was not actually made directly with ECS. it was made using nested prefabs and then Unity made their own custom script that converted those prefabs into ECS code specifically for that demo. They also used features that aren't going to be public till Unity 2019 to achieve that. ECS seems very much like the new scriptable render pipeline. The standard unity HD pipeline isn't fully baked yet but you can write your own if you want using beta tools. In reality most people are best off waiting for Unity to finish theirs instead and then building their assets around that. I think the more important thing is making assets work well with the new job system as I think that is the future. There is certainly no harm in writting new objects in the new ECS format but I think in reality most calls will still be made to ram rather than cache and Unity will either make a new form of prefab or make a general purpose script that converts prefabs to ECS at build time where the compiler or engine will decide what elements to put into cache to use it most effectively.