Before Allure we had 5 cruises with RCI. 3 on Explorer, 1 on Splendor and 1 on Brilliance. Much smaller that Allure:
Also before Allure cruised on
Celebrity (Century, Mercury, Summit) so all smaller
Holland - Zuiderdam
NCL - Sun, Dawn, Gem, Jewel, Breakaway
Carnival - Liberty, Miracle, Glory
Princess - Caribbean X 3, Ruby
When we entered Allure at age of 40+ we literally felt like kids in candy store. Very interesting ship. Never felt more crowded than other ships.
We did feel that Carnival Liberty and NCL Breakaway were very crowded. Allure was not.
It is a large ship with many people... but it is a huge ship so people spread nicely. What important is ship design and number of people to size ratio. Allure is well designed.