Builders are unique. They have their own personality, floorplans, contracts, overhead, and manufacturing standard (which must at least meet building code in Frisco, but can exceed it, as well).
There are happy owners of homes built in Willow Bay by both builders. "Better" isn't something we can tell you. It depends on you and your wishes for your next home. Your criteria would likely make one builder stand out over another. The lot the house sits on may play a factor for you. The amenities inside the home, that were selected by the builder's in-house design representative, will also appeal to you in different ways from your tour of both homes. You probably have a preference right now, and are just looking for confirmation. You aren't wrong with either pick. They both fit your budget nicely, which is a good thing. If you can see yourself being happy in that home for the next 7-10 years of your life, then you cannot make a wrong choice. It's a booming neighborhood in a very popular city that has become a hub of the North Dallas suburbs. The last 20 years have been very, very good to Frisco, TX.
Pick either one and enjoy your new home.