You should spend time in the neighborhood at different times of the day, check with the local police about crime in the area and visit the neighborhood schools to ascertain if it is a good fit for you. Talk to any neighbors that you might find out (obviously with an eye toward prudence in your questions). Lastly, you should have your own representative when dealing with any builder/builder's representative. A good Realtor will be worth his/her weight in gold comparing the new construction with exisiting opportunities. A realtor can help determine which upgrades will be best for resale for later too.
I have lived in Collierville since 1998 and in Shelby County my entire life (51yo) and I can tell you that the Collierville area is terrific, regardless of where you settle.