David, they’d probably shoot you. The dam is well guarded right now.
I’ve seen both more than once, and there is no comparison. Both are fantastic fun, but they are entirely different. I think you would learn more at Hoover, but it would be a one trick pony vacation, unless you wanted to go to Gemmorah and gamble. Sodom by the Sea (or Bagdad by the Bay as Herb used to call it) is the cool gray city of love, and the bridge (with civil war era fort underneath) is spectular engineering, architecture, transportation, romance, fun, etc.
Come of San Francisco, spend your money, ride a cable car, dine at Tadich’s, kiss your honey on the top of Twin Peaks at midnight. Catch a revival at the Castro theater and hear the mighty Wurlitzer, see the gay folks that get the fundies so riled up. Go down to City Hall and demand to meet Willie Brown in person, tell his staff you are an out of town rube and heard that he is stylish and smart (he is vain enough to want to be seen publicly by weird strangers.)
There are great museums, etc.
Or, go to Hoover dam, then go to Vegas. Lose your money on “gaming”. Eat good, but not great food cheap. See the auto museum at the Imperial. See the Cirque de Soliel and a few other shows. Shop at the Forum. I haven’t been for 5 years, so there are hotels I haven’t seen, but I usually don’t go just for the hotels.