Well, actually, you have at least three (3) choices to choose from. Here they are:
You can use the CMA feature provided by the local MLS. As the others have already noted, this is a completely serviceable CMA program. I have used the MLS Matrix CMA too, and it's okay. It needs some data "massaging" (as do most programs), and it works well for market information. If you take the class offered for free by MLS, you can learn how to put some of these great capabilities to work for you.
Now, if I'm in a rush to get comparables for an area and just need the "raw" data, Trulia offers CMA information here too. Trulia.com has a quick CMA feature for any home address you want to bring up. It will give you both the homes listed and recently sold, AND will give you the price per square foot for all of the homes in the area. To access this awesome feature from Trulia, simply type the address in the blank space at the top, and you'll get an instant listing of the homes for sale and sold next to this home.
If you want CMAs AND background information on properties, you can use Dataquick.com. This is a paid service and you can get everything on any property in California. I can get copies of deeds, the encumbrances on the home, the property profile, the list of owners for the past 10 years or more, and so much more. Also, I can get sales comparables for any home along with all of the other information. Sometimes it's helpful to know how much money is owed on the home in order to help your seller determine if its a good time to sell--well, Dataquick will provide that information for you.
So, there you go...three choices for any occasion! Good luck!
Grace Morioka, SRES
Area Pro REalty-PC
MLS Matrix will do a CMA and you can make adjustments to your comps. If you want to expand on a product, you can purchase Homeworks. Check your resources on MLS.
Have an Amazing Day!
Im not sure I understand your question. To my knowledge CMA's are run off of Proprietary software owned by the MLS. This is accessable only to Professional Licensed Realtors. Since you are one, y ou should have no trouble accessing this feature from your local MLS.