UBX versus UCX

You would only notice measurable difference when active collider count in simulation is reaching thousands.

Question, is there a huge difference in memory usage when using UBX or UCX?
Is one better than the other to give better performance after all objects have been loaded/placed in the level?

I’ve experimented with simple shapes and don’t notice an increase in kb for assets, but I’d like to know more.

Using Unreal version 4.9.2 for project purposes.

There is a performance difference and commonly UBX will be cheaper.

Do you have any screenshots that confirm this?
I’ve tried it with basic shapes and I don’t see any performance drop or higher file sizes.