In my opinion (only my opinion), it's harder for a hip hop dancer to learn to dance ballroom than vice versa. When you watch the TV show "So You Think You Can Dance," you see ballroom dancers, contemporary dancers, etc. dance hip hop choreography well, but many of these (mostly) highly trained dancers have trouble with Foxtrot or Rumba. I think (again, my opinion) that is because of the type of partnering (leading and following, etc.) required to dance ballroom well. When two hip hop dancers perform a routine they may be perfectly synchronized, but they are not dancing TOGETHER in the same way that a couple dancing Waltz in closed hold are.