Overall the Phoenix Marathon is a great race, whether you're in it for the half or the full. It has great back-end support (you can email their support team and expect a response back in a reasonable time frame. There is sufficient fuel at each aid station - ie they never run out of water, gatorade, goo, gel, etc, and always an abundance of race support, even during off years, where it may actually rain, which is rare in Phoenix.