1. Independent representation. The folks in the sales office are very nice and very helpful. They also work for the builder and are representing the builder in the transaction, not you. No matter how friendly they seem, they are not working in your best interests.
He lists nine more reasons. This is take from last year on “Default Position.”
Update 10/29/2010: Jonathan changed his site’s address, so this is an updated link to the above-referenced story,
10 Reasons to Take an Agent to a New Build
Update 11/9/2017: Welp … the link above is now dead. So much knowledge into the ether.