Every cruise claims to be a luxury cruise and every ship claims to be a luxury ship. Indeed, some newer, larger mass-market cruise ships have dining rooms and public areas much more opulent and luxurious than you will find on a luxury cruise ship.
It has a lot to do with size. The mega cruise ships have bars, restaurants, artwork and public areas that are designed to wow. Holland America's Eurodam has a beautiful Asian-themed restaurant and bar with stunning views. The mainstream cruise lines can provide "grand." You'll never get that on a small luxury ship.
The primary difference is smaller luxury cruise ships provide more personal service and more personal space. It's more about you than it is the ship. The cabins are larger and usually all have balconies; dining is usually open seating; drinks and wine are usually included. If you want a shrimp cocktail and steak delivered to your room and midnight you can probably get it.
The advantage of a luxury cruise comes down to four basic points:
1. No waiting in lines and more space for passengers.
2. More personal attention from a proportionately larger staff. On a luxury cruise there are usually two crew members for every three passengers. On a regular cruise it's one crew member for every two passengers.
3. A more sophisticated group of fellow passengers.
4. No nickel and diming.
The last point seems to make the biggest difference for most luxury cruisers. Passengers hate taking out that cruise card to charge anything, whether it be drinks, wine, tours, or activities.
The luxury cruise lines are pretty much all-inclusive, if not totally all-inclusive. Regent, the line I'm sailing, is completely all-inclusive. Once on board you don't have to charge anything and you don't have to tip anything, unless you buy something in the shops or the spa. It's possible to complete your cruise and have a final bill of zero. With booking promotions and incentives you will often have a credit on your account when you begin the cruise, forcing you to spend money buying things on the cruise to use up your credit. For example, my on board credit was $950.
The all-inclusive nature of a luxury cruise changes the dynamic of the cruise experience. Since drinks are already included, there is much more socializing in the bars and lounges before and after dinner. You can invite friends for drinks without worrying about who is paying. It really is a very different atmosphere from a cruise where you pay as you go. Some passengers will tell you this is why they will never take a regular cruise again.
The food on a luxury cruise is somewhat better than a regular cruise but the service and dining atmosphere are much better. Luxury cruise lines have several choices for dinner, all usually included in the fare; no surcharges. There are four gourmet dinner restaurants on my ship, plus room service.
Luxury lines also have anytime dining. In the main dinner restaurant you can walk in and be seated whenever you wish and there is enough seating capacity to handle it. The premium lines have also moved in this direction but if you arrive for dinner at a peak time you may have to wait for a table.