Rotational speed matters mostly for latency. If you are looking for small files, or moving them around your disk, then yes it matters. If you will be dealing with large files, or video files etc, then both will perform very similar.
Loading times depend on the game - if a game is using/loading large files, then you will not see much difference between the two.
Of course if you go SSD you can smoke the other two and be a happy man that never looked back!