Welll.... more specific questions would be better, but here goes.
Crystal is a luxury cruise line but it is different from the other luxury lines. They really put the focus on the most excellent food and service anywhere.
Their ships carry about 1000 people unlike other luxury cruise lines that only carry about 300. This means they can offer more fun activities onboard.
The food is by far the best I have had on any cruise line - I mean five-star better, a world of difference.
They have great lecturers like baseball players, world travelers, broadway show producers, etc.
I LOVE the alternative dining restaurant, the Asian one (I forget the name) has a menu by the famous Nobu. The Italian restaurant is so delicious I can't explain it.
The bathrooms are beautiful - walkin closets, jacuzzi tubs, four-jet showers, dual sinks. King-sized beds (not queens), balconies big enough to have breakfast on. Room service will bring you an entire meal and set up a table on the balcony.
The buffets have all the shrimp and crab you can eat, plus lobster claws. The pool area serves a fantastic 1-inch thick hamburger or a hot pizza.
The entertainment is top-rate, great dancing to a live band, etc.
Yes, it costs more, but a day at sea on Crystal is the best anywhere.