Many cruisers have written reviews of Antarctica's spectacular, otherworldly beauty. I second those. It was incredible -- a cruise I'd gladly take again.
Ditto you can get information about the food, entertainment, cabins elsewhere. So I'm going to write about some of the practicalities.
First, Argentina charges citizens of some countries, including the U.S. and Canada, a "reciprocity fee." It's super-important to pay this fee online and get the printed confirmation before leaving on the trip because you can't enter the country otherwise. www.provinciapagos.com.ar. Our paperwork was checked half a dozen times. Chile also has an entry fee, but apparently you only have to pay it if you fly into Chile, which we obviously didn't as our cruise ended there. (I'd double-check to make sure Chile's rule hasn't changed.)