I really like this feature of rsync (trailing "/" means copy the directory contents to the dest, no trailing "/" means copy the directory itself). Other tools, like cp, don't have any way at all to say copy the directory contents to the dest, and for those tools the result depends on whether or not the destination already exists and is a directory (you might end up with a duplicate nested directory). Rsync produces the same result whether the destination already exists or not.
Depending on the shell, `somedir/*` excludes files whose names start with "." and may expand to a literal "*" if there are no file names to expand to. Basically, globbing has more edge cases to deal with.
