How much space is reserved to the underlying collection behind a method using yield return syntax WHEN I PERFORM a ToList() on it? There's a chance it will reallocate and thus decrease performance if compared to the standard approach where i create a list with predefined capacity?

The two scenarios:

    public IEnumerable GetList1()
    {
        foreach( var item in collection )
            yield return item.Property;
    }

    public IEnumerable GetList2()
    {
        List outputList = new List( collection.Count() );
        foreach( var item in collection )
            outputList.Add( item.Property );

        return outputList;
    }