My daughter is having a home built by Crown Communities and has encountered a number of problems. The most significant is that the size of three of the bedrooms and the laundry room is substantially less than expected. Be sure to get a blueprint showing exact room size before they start construction and get a rendering of how the exterior will look.
I have been into Harrison Mill Estates before with a client, and I liked what I saw. Nice homes, decent lots, good floorplans. Looked to be well-built from what I could tell, and I'm kind of picky. I have to assume this is the neighborhood you are referring to. It's a Conyers address and Loganville and Youth schools.
I have dealt with the agent that was in Oakmont when they first opened it. I believe this was a Crown Communities neighborhood. The homes are a little more basic than Harrison Mill, but still very nice. No problems, but keep in mind that the agents there are actually part of the same company as the builder, so they use their own contracts and don't really care about your specific needs. Take a realtor. I can tell you that it will cost you the same with your own realtor, and probably a lot less.
Loganville is my area, I am very familiar with it. I would be happy to assist you and make sure you're covered. Feel free to call me at 678-362-3138.