Some experts argue no. But passengers seem to be happy, and even in this economy, Celebrity Solstice is sailing near full -- and getting a higher price than other Celebrity ships, say travel agents.

''We just loved it,'' says Sheila Nadell of Miami. She and her husband, Alan, have sailed with Celebrity 44 times. ``The service was great, the dining rooms were gorgeous. It had wonderful music -- not as stuffy as it sometimes is.''

Still, the Nadells say they prefer the smaller size of Celebrity's Century, which carries 1,800.

For passengers -- even those familiar with Celebrity -- knowing which ship to choose can be challenging. Like Holland America, Celebrity has a sizable fleet -- nine ships -- and size, style and amenities vary. Though most ships carry 2,000 passengers or more, Celebrity Xpedition -- which sails the Galapagos islands -- carries only 92.

What remains constant: High-quality art collections, fine dining and an active, sophisticated ambience that's a hit with the 45-60 set.

HOLLAND AMERICA

Founded in 1873, Holland America retains an air of maritime tradition, and even on its newest ship, Eurodam, you'll find ship models and maritime paintings mixed in with more contemporary touches.

For many cruisers -- even college student Becky Holtrop of Michigan -- the ambience is part of the appeal. ``I like the traditional feeling. I guess it depends on your personality.''

Holland America also clings to the idea that smaller is better, so while its ships have grown in size over the years, the largest still holds only 2,100 passengers at double occupancy. That medium size -- far smaller than the largest contemporary ships, which hold up 5,400 -- suits Miami passenger Karen Leibowitz, who sailed with Holland America to both Canada and the Black Sea. ``We prefer it to tiny ships because there's more to do.''

She also preferred the lines' beyond-the-typical sailings. Holland America ships offer hundreds of itineraries ranging from familiar, seven-day Caribbean voyages to an 108-day world cruise.

Holland America' average passenger age is 57, and when schools are on holiday, the children's programs and play spaces are lively. But on other sailings, say experts, most passengers are past Social Security age, and the ships take on a quieter atmosphere. Dining is by assigned time, though diners can opt to ''stand by'' at other times. Several formal nights are held during each sailing.

With 14 ships ranging in size from 793 to 2,106 passengers, facilities and shipboard experience vary. To smooth the differences, the line instituted a $525 million Signature of Excellence program bringing new lounges, eateries, verandas and upgrades throughout its fleet; all enhancements should be completed by 2011. On all ships, most service staff is Asian, and many crew members have worked with the line for years.

That's an added attraction for Holtrop, who has taken 29 cruises with her family, 19 of them aboard Holland America. ``The staff remembers you, even four years later. It feels like home.''