I don't know either but I agree with
@Juampa1989 keep what you have if it is clear.
- As a loudspeaker engineer my vague rule of thumb is to get a clear total improvement in a speaker (instead of just trading for different imperfections) you need to spend like 3X as much.
- Some places (Crutchfield for one so I hear) will let you try at home with inexpensive return/restock fees.
- 3-way systems with a separate midrange will tend to have clearer vocals. Maybe not always, but the dedicated midrange helps from a design point of view.