execution(* *..ProductManager.*(..))
means that, "for all the methods in the ProductManager class"
tx:advice settings are not additive. It says that for all methods beginning with save use the default transaction settings. For the others, this setting means they are NOT read-only transactions.
For the common sense, one would expect
<tx:method name="save*" read-only="false" />
<tx:method name="*" />