I chose this cruise as a surprise Christmas present for my wife. We had been away from cruising for a couple years, and I remembered our Antarctic cruise with Crystal - just how great it was. Never been to Brazil, and now to see the refurbished Symphony - this was almost a "no brainer."
I'm still a fan of traditional dining (not "any time"), and Crystal did that very well in the past. I'm afraid that is a thing of the past, unfortunately. I miss the friendships developed over the dining table, but replaced that with friendships made on Cruise Critic's Roll Call.
Ports are nothing to get too excited about. Snorkeling at Buzios was wonderful (although the sea is a bit rough getting to the snorkeling site). Had a great time horseback riding in the Argentine pampas. Days at sea are always wonderful on Crystal - so busy with educational lectures, shows, dancing, spa appointments, and (of course) eating - the ports are not necessarily all that important.
Size of the cabin suited us perfectly. Plenty of room and storage. Big jacuzzi tub. Convenient location. Big screen television.
Very good snorkeling at local islands.
Probably more hype than substance. You can do this in a couple days. You are constantly warned about crime, which definitely detracts from the experience.