Silver Explorer (Prince Albert II) has had positive feedback in my office. I visited the ship and thought it was more than comfortable. Last winter The World Ship also did an Antarctica spin, but without the same level of natural engagement that Silverseas does.
I went on the ship when it was Prince Albert II, and loved it. I got a suite, which had a living room, bedroom, huge walk-in closet, and marble bath with separate shower and tub, floor to ceiling windows and very small balcony.
The naturalists aboard were so knowledgable, and we went on excursions daily....weather permitting!
The experience was one I wouldn't trade for anything. Go, if you have the chance.