Secondary command buffer granularity

This is sort of a question which probably needs benchmarking to answer properly.
But maybe some of you already did this and can share some experiences. With “granularity” I mean the number of draw-calls per secondary command buffer. The vulkan samples (“hologram” for example) uses one draw call per secondary command buffer. This seems quite inefficient to me, because you would have to rebind everything for every single draw call, since the every command buffer has its own state. An alternative would be to batch draw calls in secondary command buffers.
I think it all depends on whether Vulkan actually “rebinds” the same pipeline and description sets for every command buffer, even though they are the same as in the previous command buffer.
Do you have any experience with this?