Sort or sort the collection

Suppose an application creates several data structures HashMap<String, MyClass>, each of which contains from tens to hundreds of Comparabletype objects MyClassthat must end with one and sorted Collection.

Two possible implementations of this function return a SortedSet or sorted list, as shown below:

public static Set<MyClass> getSortedSet(HashMap<String, MyClass>... allMaps)
{
    SortedSet<MyClass> set = new TreeSet<MyClass>();

    Collection<MyClass> c;

    for (HashMap<String, MyClass> map:allMaps)
    {
        c = map.values();
        set.addAll(c);
    }

    return set;
}

public static List<MyClass> getSortedList(HashMap<String, MyClass>... allMaps)
{
    List<MyClass> list = new ArrayList<MyClass>();

    Collection<MyClass> c;

    for (HashMap<String, MyClass> map:allMaps)
    {
        c = map.values();
        list.addAll(c);
    }

    Collections.sort(list);

    return list;
}

Was there any clear performance advantage for any of the above methods?

Is there a faster way to implement the same functionality?