-@warning <b>S4U is not as rock stable as the rest of SimGrid yet</b>.
- You are really welcome to test it, but be warned that the API
- may change without notice between releases. This is however
- the way to go if you want to create a new long-term project.
- If you want to play safe, proceed to @ref MSG_API instead.
+Currently (v3.21), S4U is definitely the way to go for long-term
+projects. It is feature complete, but may still evolve slightly in the
+future releases. It can already be used to do everything that can be
+done in SimGrid, but you may have to adapt your code in future
+releases. When this happens, compiling your code will produce
+deprecation warnings for 4 releases (one year) before the removal of
+the old symbols.
+If you want an API that will never ever evolve in the future, proceed
+to the deprecated @ref MSG_API instead.