I couldn't find out anything about Brentwood before we purchased in the Preserve at Forest Creek either.... We looked all over Union County and in my opinion, they are a very good builder. The thing that really sold us in this community was the lot size and remote neighborhood. It's very quiet - with the exception of the train from time to time.
The build quality was excellent. The construction seems to be very tight. They are a "green builder" so they have to conform to those standards. The salesman has been very helpful and we were able to make some custom changes within reason. (try to negotiate those up front). You can obviously get a very good deal on a house right now... it's a buyers market.