Smaller than containers seems unlikely since a container doesn't have any kernel at all, while these microvms have to reproduce at least the amount of kernel they would otherwise need (e.g., a networking stack). I'm sure some will be inclined to compare an optimized microvm to an application binary slapped into an Ubuntu container image, but that's obviously apples/oranges.

Faster might be possible without the context switching between kernel and app? And maybe additional opportunities for the compiler to optimize the entire thing (e.g., LTO)?

container can be smaller at rest, but larger at runtime

if you're not sure which you want its probably container