We have only used an upper bed on older Carnival ships. We kept them down 24/7 because the boys like to sit up there during the day or while getting ready for dinner. The pullmans are in the ceiling and the cabin steward has a key to bring it down. We have never used a pullman so I can't help you with which one is better.
Teresa and Larry
#36-Carnival Splendor 9/16/12
7 night Mexican Riviera
#37-Allure of the Seas 11/11/12
7 night Eastern Caribbean