I have the Chameleon 7" components in my rear doors and they are absolutely stunning. Great clarity, very smooth sound without being too harsh, and they get PLENTY loud if you choose. Oh, and the Midbass is great if you put them in an enclosure or an IB.
I heard the alpine X's and actually preferred the Chameleons as well as the MB Quarts that I have in my front doors over them.
You really just need to hear them all and see what your ears would like best and consider what would sound best in your vehicle.
Let us know what you get.
Jester