My understanding is that if you are just doing the exact same work that regular vertex shaders would do, you are better off sticking with the regular pipeline.

My understanding is that if you are just doing the exact same work that regular vertex shaders would do, you are better off sticking with the regular pipeline. Might even be faster, since the old pipeline (potentially, depending on implementation) has a bunch of fixed-function hardware that gets disabled for mesh shaders. The preformance advantages only come when you can take advantage of the flexibility to apply new optimisations. Such as sharing work across a mesh invocation, or avoiding launching mesh invocations from task/amplification shaders, or avoiding vertex fetch (procedural generation).