If you can get a good deal on a suite, yes, they are worth the money.
However, if the rates are over $2000 per person, I don't think they are worth it. You could go HAL in a full suite for less money. My last three Royal suites were: April 2001 Galaxy $2000ppdo, Nov 2001 Century 1877-single occupancy, Dec 15, 2001 $1537-single occupancy.
In April I booked a Cat 1 guarantee and my agent forced the upgrade to a Royal. Nov - I booked a Royal Suite, and for my upcoming cruise, I booked a Sky Suite... and again my agent got me the upgrade to a Royal Suite.