To follow up what Mike has said:
1. We all think it's great that Trulia provides a forum for you to get questions answered in a semi-anonymous fashion. It is our obligation to answer those questions truthfully, as we each feel is appropriate.
2. In following some of the (several) questions you've asked in the last 7-10 days, it seems clear you're not an experienced Buyer and that you're unfamiliar with the Cary/Apex/Morrisville area.
3. It's up to you to choose a Realtor to help you navigate the important undertaking of buying a home. If you've visited onsite at the 3 different (or more) communities you've mentioned, then those agents represent their Seller/Builder and NOT YOU. And so, they are all going to point out the reasons to buy in THEIR community, not others.
4. When you decide which Realtor will represent you, then that agent will provide their unvarnished yet professional opinion of each neighborhood. They'll help you understand the best home for your needs. And they'll help you get the best deal possible on the home, and probably on your mortgage.
5. So - your decision does NOT need to be which of these communities is best, and go into the sales center "unarmed" and buy a home because you've done a lot of research on the internet and you can handle everything involved with purcashing a home by yourself.
Your decision is WHO TO HIRE to be your Realtor and be your Buyer's Agent.
Now, to try and answer your question -
if all you are asking is which is a better location, then the only way to know is to ask:
are you asking about proximity to recreation/amenities?
everyday shopping?
work? lower traffic/shorter commute?
some other geographical need?
and since you're most interested in new construction:
1. which one is least likely to have the "next" new subdivision built 1/2 a mile away?
2. which subdivision has the fewest remaining homes to be built? - Sat Dec 26 2009, 19:42