This is what I am interested in as well.
From what I recall from our own research.
-Very expensive. (No big deal here).
-Very unreliable schedules due to weather irrops. (I guess you can take the risk if money is no object and you don't have individuals paying their own way).
-Very little baggage allowed. (Seems like they had most stuff brought in on a boat and won't be in Antarctica for very long?)