Don't let the hot Texas sun overheat your home.
Many products in use today cannot compete with the scorching Texas sun. In 2011, mother nature came down and let us know that WWII insulation was not going to cut it any more. Everyone is going to need some form of foam insulation. In some cases, you may decide on a hybrid.
Everyone has to consider their budget, the amount of the house getting a direct hit from the west. It is the afternoon sun that is going to hurt. Steady state is going to be equal by noon in many houses, two or three at the latest in all but the newest and best installed fiberglass batts houses. If you do not have a hybrid or foam house, you better not have exposure to the western sun.