The buses don't stop as close to all the sights as they make it seem. For some you have to walk a few blocks from the bus stop. Next, the buses only run every 30 minutes vs every 20, and the double decker buses only run a few times a day. The buses only run til 5:30pm, so better plan accordingly. They don't warn you that stops are altered for events or construction so some may be skipped. The "free" Alamo access is already free but you still have to pay for audio or guided tours, including access to the main church and exhibits. I might save my money if I were you.