I really like USH, have an annual pass for it, (it's closer to me than DLR), but if I was coming from out of town, and had to pick between USH and DLR, DLR would win every time. USH has some great rides and attractions, and the backlot tram tour is a true original (Disney MGM Studios tried to recreate it, but it just couldn't compare). But most of the other attractions at USH have comparable attractions at DLR. So it's really a matter of taste, time, and money. USH is defintely doable in one single day, and if you are in the Hollywood area during your vacation, it's really close, in fact you can take the subway from Hollywood Blvd. to Universal for a couple of bucks and save $ on parking.