Discovery World Cruises is a brand-new company, so it is difficult to rate their cruise experience. I visited the M/V "Discovery" this summer, while she was chartered to the UK's Voyages of Discovery. A photo review is available here
Discovery World Cruises is headed by Gerry Herrod who also founded Orient Lines. Therefore, expect the experience to be similar to that offered on Orient Lines' "Marco Polo". DWC has also taken over key staff from Orient Lines.
Therefore, in theory I consider the "Discovery" to be one of the best three choices for Antarctica cruising, together with Hapag-Lloyd's "Hanseatic" and the "Marco Polo".