Using include
alone is probably not enough to yield any noticeable change to rendering time. It also shouldn't have an effect on the view hierarchy: you should get the same hierarchy regardless of whether portions of it are included from a separately-inflated layout.
(I suppose the LayoutInflater could be caching recently-inflated resources, potentially making it faster to inflate a layout that is composed of recently-used included
pieces. But it seems unlikely, and unless you have benchmarked it in your app, this would be a needless micro-optimization IMO.)
What include
is good for is organization of your layouts, in particular, breaking out reusable pieces. Romain Guy, author of much of the Android layout system, wrote a blog post a few years back showing some tips/tricks that are possible with include, for example using it to separate orientation-sensitive layouts from more generic ones.
By contrast, ViewStub is intended for layout inflate time optimization; it allows portions of your View hierarchy to be lazily inflated.